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Do You Throttle All The Way Down Before Turning Off The Engine?
#1
Z
Zeroturner
Z
Zeroturner
Or, when you quit mowing, do you shut down the engine at full throttle and not concern yourself about it?
My old tractor style 46" deck, Craftsmen, powered by a 24 Hp, B & S Intek engine's manual never mentioned having to do this. So, I always left it going full blast when I killed the engine. I sold it to my next door neighbor with 350 hours on it and he is now running it with over 500 hours on it and he doesn't worry about shutting it down at idle.
My Toro manual says to idle all the way down, wait a minute and then turn off the engine.
What do you guys say?
My old tractor style 46" deck, Craftsmen, powered by a 24 Hp, B & S Intek engine's manual never mentioned having to do this. So, I always left it going full blast when I killed the engine. I sold it to my next door neighbor with 350 hours on it and he is now running it with over 500 hours on it and he doesn't worry about shutting it down at idle.
My Toro manual says to idle all the way down, wait a minute and then turn off the engine.
What do you guys say?
#2
DSepe
Didn't do on my rider for 26 years because manual didn't say. Now I just do it because my zero turn manual says so. I just stick with manual.
DSepe
Or, when you quit mowing, do you shut down the engine at full throttle and not concern yourself about it? My old tractor style 46" deck, Craftsmen, powered by a 24 Hp, B & S Intek engine's manual never mentioned having to do this. So, I always left it going full blast when I killed the engine. I sold it to my next door neighbor with 350 hours on it and he is now running it with over 500 hours on it and he doesn't worry about shutting it down at idle. My Toro manual says to idle all the way down, wait a minute and then turn off the engine. What do you guys say?
Didn't do on my rider for 26 years because manual didn't say. Now I just do it because my zero turn manual says so. I just stick with manual.
#3
M
mechanic mark
M
mechanic mark
Absolutely, at least 30 seconds at low idle before shutting down. I can't recall hearing or seeing anyone press their vehicle gas pedal to the floor and holding it before switching the the key to off.
#4
Ric
I idle all the way down on my GS because like DSepe said the manual say to. I've always idled down on all my mowers before shutting off.
Ric
Or, when you quit mowing, do you shut down the engine at full throttle and not concern yourself about it?
My old tractor style 46" deck, Craftsmen, powered by a 24 Hp, B & S Intek engine's manual never mentioned having to do this. So, I always left it going full blast when I killed the engine. I sold it to my next door neighbor with 350 hours on it and he is now running it with over 500 hours on it and he doesn't worry about shutting it down at idle.
My Toro manual says to idle all the way down, wait a minute and then turn off the engine.
What do you guys say?
I idle all the way down on my GS because like DSepe said the manual say to. I've always idled down on all my mowers before shutting off.
#6
I
ILENGINE
I
ILENGINE
Some I idle down just because I don't like shutting them off at full throttle. Push mower engines are shut off at full throttle every day since there is no throttle control. Some engines like Kohler have to shut them down at full throttle due to the design of the carb that will cause afterfire if shut down at idle.
#7
R
Rivets
R
Rivets
Always idle down. Always try to tell our customers with riding units to do the same, as most don't read the manuals. Engines manufactures tell us that the reason is to reduce the amount of unburnt fuel which enters the engine and then the atmosphere. I don't really believe them but do pass it along if they customer asks why.
#8
S
SeniorCitizen
S
SeniorCitizen
I've retired from industrial engines that always shut down at full throttle when un-attended. 1,000 HP to 2,000 HP it made no difference. Briggs Vanguard, regarded as one of the best small engines, always starts at full throttle and shuts down at full throttle on many applications.
My lawn tractor, always at low idle rpm unless a swarm of bumble bees are after me then I bail and run the best I can and to hell with that tractor.
So I suggest either way, what ever makes you happy.
My lawn tractor, always at low idle rpm unless a swarm of bumble bees are after me then I bail and run the best I can and to hell with that tractor.
So I suggest either way, what ever makes you happy.
#9
robert@honda
robert@honda
On walk-behind mowers, there is no genuine need or benefit to slowing the engine down before shut-down. One marginal exception would be a mower with a flywheel brake (engine and blades both stop when you let go). If you reduce the engine speed before shut-down on this type of mower, it could fractionally reduce the wear on the flywheel brake pad(s) ever so slightly. It is an insignificant amount.
Other mowers with blade brake clutch (only blades stop when you let go) usually have the engine stop switch built into the throttle control, so you have to move it from FAST to SLOW before getting to STOP anyway. No flywheel brake pads on these models, so no benefits to slowing the engine before shut down.
Most walk-behind mowers have gravity-feed fuel systems, so the fuel pressure is very slight into the carburetor, and the chance of backfire from excessive unburned fuel getting into the engine is quite rare.
Many modern walk-behind mowers don't even have a throttle control, and run wide-open at start and stop. Extensive testing has shown such fixed-throttle designs do not cause cause any shorter engine life or operational problems (at least not here at Honda). In fact, warranty data reveals the absence of throttle controls and cables actually reduced overall repair frequency caused by damage to the throttle control cable from kinks, snags and stretching/wear.
For riding equipment that uses a fuel pump, the fuel pressure to the carburetor is higher, and to prevent backfiring, many engines have a fuel-cut solenoid/valve that instantly cuts fuel flow when the engine is switched off. So it does not matter (as far as backfiring risk goes) to reduce the engine speed or not.
Other mowers with blade brake clutch (only blades stop when you let go) usually have the engine stop switch built into the throttle control, so you have to move it from FAST to SLOW before getting to STOP anyway. No flywheel brake pads on these models, so no benefits to slowing the engine before shut down.
Most walk-behind mowers have gravity-feed fuel systems, so the fuel pressure is very slight into the carburetor, and the chance of backfire from excessive unburned fuel getting into the engine is quite rare.
Many modern walk-behind mowers don't even have a throttle control, and run wide-open at start and stop. Extensive testing has shown such fixed-throttle designs do not cause cause any shorter engine life or operational problems (at least not here at Honda). In fact, warranty data reveals the absence of throttle controls and cables actually reduced overall repair frequency caused by damage to the throttle control cable from kinks, snags and stretching/wear.
For riding equipment that uses a fuel pump, the fuel pressure to the carburetor is higher, and to prevent backfiring, many engines have a fuel-cut solenoid/valve that instantly cuts fuel flow when the engine is switched off. So it does not matter (as far as backfiring risk goes) to reduce the engine speed or not.
#11
djdicetn
Another throttle setting to consider is when you engage or dis-engage the blades(PTO). Most mfr's recommend 1/2 to 3/4 throttle to avoid too much initial strain on the clutch. My Gravely manual states 3/4 and that's what I use. And of course there are some users in the past that have mowed at less than full throttle(thinking they would save gas and still get the yard mowed). I've never seen any mfr's suggest anything other than full throttle when mowing and it's a consensus here on the forums that this can cause damage to the equipment.
djdicetn
Thanks to everyone for your helpful/educational information.
I'm still learning...
Another throttle setting to consider is when you engage or dis-engage the blades(PTO). Most mfr's recommend 1/2 to 3/4 throttle to avoid too much initial strain on the clutch. My Gravely manual states 3/4 and that's what I use. And of course there are some users in the past that have mowed at less than full throttle(thinking they would save gas and still get the yard mowed). I've never seen any mfr's suggest anything other than full throttle when mowing and it's a consensus here on the forums that this can cause damage to the equipment.
#12
robert@honda
Faster spinning blades = best overall cut quality. Slow-spinning blades will not cut grass smoothly, the blade is more likely to stall/stop, and the clippings won't be blown out from the mower deck onto the lawn or into the grass bag.
Always keep the throttle set to maximum speed when mowing for a clean cut and the best overall finish.
Don't use the throttle to change the mower's driving speed. Shift gears or adjust the speed control levers to slow down/speed up the drive wheels.
robert@honda
I've never seen any mfr's suggest anything other than full throttle when mowing and it's a consensus here on the forums that this can cause damage to the equipment.
Faster spinning blades = best overall cut quality. Slow-spinning blades will not cut grass smoothly, the blade is more likely to stall/stop, and the clippings won't be blown out from the mower deck onto the lawn or into the grass bag.
Always keep the throttle set to maximum speed when mowing for a clean cut and the best overall finish.
Don't use the throttle to change the mower's driving speed. Shift gears or adjust the speed control levers to slow down/speed up the drive wheels.
#13
Z
Zeroturner
Z
Zeroturner
I'm a little confused.
Are you saying that you should engage the blades at 3/4 throttle?
And, when disengaging - same thing?
Thanks!
Are you saying that you should engage the blades at 3/4 throttle?
And, when disengaging - same thing?
Thanks!
#14
djdicetn
Yep...1/2 to 3/4 throttle(either would be much better on the clutch than full throttle). Of course after engaging and before beginning to mow increase to full throttle. Check your Owner manual/Engine Manual to see if there is a suggested recommendation for engaging/dis-engaging the PTO.
ALso, another little tidbit....I used to drive my Gravely(not mowing, just to from storage) at the lowest throttle setting. Another user here that I trust recommended NOT doing that because (A)the hydros are designed to drive the ZTR at full throttle and (B)the engine doesn't cool adequately when under load at a setting other than full throttle. I did notice my hydros "whined" a bit when I transported the ZTR at the lowest throttle setting and so I am no longer doing that(an ounce of prevention.........:0)
djdicetn
I'm a little confused.
Are you saying that you should engage the blades at 3/4 throttle?
And, when disengaging - same thing?
Thanks!
Yep...1/2 to 3/4 throttle(either would be much better on the clutch than full throttle). Of course after engaging and before beginning to mow increase to full throttle. Check your Owner manual/Engine Manual to see if there is a suggested recommendation for engaging/dis-engaging the PTO.
ALso, another little tidbit....I used to drive my Gravely(not mowing, just to from storage) at the lowest throttle setting. Another user here that I trust recommended NOT doing that because (A)the hydros are designed to drive the ZTR at full throttle and (B)the engine doesn't cool adequately when under load at a setting other than full throttle. I did notice my hydros "whined" a bit when I transported the ZTR at the lowest throttle setting and so I am no longer doing that(an ounce of prevention.........:0)
#15
Carscw
Carscw
I engage the pto at 3/4 throttle on every mower but my snapper. And disengage at around 1/3. No real reason that I disengage so low. I just like to.
The snapper is my wet tall thick grass mower. Engine RPMs around 5000.
I engage at full throttle after I disengage to let the clippings fall out of the deck.
The snapper is my wet tall thick grass mower. Engine RPMs around 5000.
I engage at full throttle after I disengage to let the clippings fall out of the deck.
#16
Fish
Engine rpms @ 5000?????
Just go out, start the damn thing mow with it then shut it off!!!! It is not the Space Shuttle, or a big diesel engine with a turbo....
Fish
I engage the pto at 3/4 throttle on every mower but my snapper. And disengage at around 1/3. No real reason that I disengage so low. I just like to.
The snapper is my wet tall thick grass mower. Engine RPMs around 5000.
I engage at full throttle after I disengage to let the clippings fall out of the deck.
Engine rpms @ 5000?????
Just go out, start the damn thing mow with it then shut it off!!!! It is not the Space Shuttle, or a big diesel engine with a turbo....
#17
Carscw
Carscw
Yes fish 5000 RPMs It is rated to do 6000 RPMs Bet they did not teach you about the REV KIT when you pretended to go to parts replacer school.Engine rpms @ 5000????? Just go out, start the damn thing mow with it then shut it off!!!! It is not the Space Shuttle, or a big diesel engine with a turbo....
#18
Fish
Fish
Yeah baby!!!! Does your Snapper friends know all of this????
#19
Fish
Fish
Oooops, I didn't mean "friends"..... So some engine Co. supports your practice?
#20
Carscw
The kit is sold so the engine can handle the higher RPMs
Very easy to get high RPMs and 50hp out of a briggs 20hp v twin.
New source of V-Twin performance parts!
Low buck $410
16hp heads $75
Thin head gaskets $40
Precision cam $175
Rev kit $75
K&N air filter $35
Rejet carb $10 for jets
mid buck build maybe 40hp $1500
ARC billet aluminum flywheel for starters. $320 http://www.arcracing.com/cgi-bin/Sof...exe/?E+scstore
Starter to go with flywheel $175
Precision Camshaft cost about $175
Modified carb $175 up from EC Distributing
Air cleaner & adapter $150
Roller rockers $300 - if you have the good aluminum rockers you wont need these.
Port & polish heads $150
ARC rods $220 http://www.arcracing.com/cgi-bin/Sof...exe/?E+scstore
Thinner head gaskets $35
Also a interesting point was to bolt 16hp heads on a 18-20hp motor to pick up some compression
High end build 60hp build! will run at 7000 rpm at the race track!
Cam 1200 Precision
Longer than stock Rods
Using the longer rods you cut the stock pistons 100 thousands creating flat tops and more compression. new rings
Now outside several options. 16hp heads again smaller chamber and more compression
new unported Or ported and all the works, springs and retainers
Billet flywheel
High torque Starter
two steel push rods to replace aluminum
have that carb built to the hilt
K&N Airfilter
Air filter adapter
Roller rockers
K&N filter for crank case breather
Gasket set to include very thin aluminum gaskets (more compression)
Carscw
Oooops, I didn't mean "friends"..... So some engine Co. supports your practice?
The kit is sold so the engine can handle the higher RPMs
Very easy to get high RPMs and 50hp out of a briggs 20hp v twin.
New source of V-Twin performance parts!
Low buck $410
16hp heads $75
Thin head gaskets $40
Precision cam $175
Rev kit $75
K&N air filter $35
Rejet carb $10 for jets
mid buck build maybe 40hp $1500
ARC billet aluminum flywheel for starters. $320 http://www.arcracing.com/cgi-bin/Sof...exe/?E+scstore
Starter to go with flywheel $175
Precision Camshaft cost about $175
Modified carb $175 up from EC Distributing
Air cleaner & adapter $150
Roller rockers $300 - if you have the good aluminum rockers you wont need these.
Port & polish heads $150
ARC rods $220 http://www.arcracing.com/cgi-bin/Sof...exe/?E+scstore
Thinner head gaskets $35
Also a interesting point was to bolt 16hp heads on a 18-20hp motor to pick up some compression
High end build 60hp build! will run at 7000 rpm at the race track!
Cam 1200 Precision
Longer than stock Rods
Using the longer rods you cut the stock pistons 100 thousands creating flat tops and more compression. new rings
Now outside several options. 16hp heads again smaller chamber and more compression
new unported Or ported and all the works, springs and retainers
Billet flywheel
High torque Starter
two steel push rods to replace aluminum
have that carb built to the hilt
K&N Airfilter
Air filter adapter
Roller rockers
K&N filter for crank case breather
Gasket set to include very thin aluminum gaskets (more compression)
#21
Carscw
Carscw
This is a high rev kit with offset flywheel key.
#22
Fish
Fish
So "slightly" advancing a flywheel key is it??????? Boy, they found some real "suckers".........
#23
Carscw
No fish
Longer push rods and better keepers
And spring spacers so you don't float a valve.
I guess you would know better then everyone else that gets 50 hp out of a briggs intek.
I understand that what you can not comprehend scares you and gives you low self-esteem and the only way you can cope with it is to put others down and insult them.
What you really need is a sting rope and a tall tree
Carscw
So "slightly" advancing a flywheel key is it??????? Boy, they found some real "suckers".........
No fish
Longer push rods and better keepers
And spring spacers so you don't float a valve.
I guess you would know better then everyone else that gets 50 hp out of a briggs intek.
I understand that what you can not comprehend scares you and gives you low self-esteem and the only way you can cope with it is to put others down and insult them.
What you really need is a sting rope and a tall tree
#24
serelaw
serelaw
Carscw
This is great news.
I wanna hot rod my B&S.
Do you have any links I can read about this stuff?
I wanna do it on my M ZT-52.
Sometimes it's Sinatra strippers and scotch.
This time it's build the ZT motor.
Or I guess get another engine and build that to throw in.
I've seen mower races on tv; I never thought to check out the high performance stuff.
I can live with 40-50 HP. I do want to run premium not alcohol.
So realistically, just head work and a cam, and jet, push rod,s keepers and gaskets I could
make some great torque. Crap then a forged rod and crank maybe? I have a head guy and this sounds doable.
Should not take too much to give it some more ummph.
This is great news.
I wanna hot rod my B&S.
Do you have any links I can read about this stuff?
I wanna do it on my M ZT-52.
Sometimes it's Sinatra strippers and scotch.
This time it's build the ZT motor.
Or I guess get another engine and build that to throw in.
I've seen mower races on tv; I never thought to check out the high performance stuff.
I can live with 40-50 HP. I do want to run premium not alcohol.
So realistically, just head work and a cam, and jet, push rod,s keepers and gaskets I could
make some great torque. Crap then a forged rod and crank maybe? I have a head guy and this sounds doable.
Should not take too much to give it some more ummph.
#26
Fish
Fish
So "longer pushrods" is all?
#27
Fish
Fish
"Better Keepers" means "What???'.
#28
Fish
You have at least 1 follower.....
Fish
Carscw
This is great news.
I wanna hot rod my B&S.
Do you have any links I can read about this stuff?
I wanna do it on my M ZT-52.
Sometimes it's Sinatra strippers and scotch.
This time it's build the ZT motor.
Or I guess get another engine and build that to throw in.
I've seen mower races on tv; I never thought to check out the high performance stuff.
I can live with 40-50 HP.
You have at least 1 follower.....
#29
serelaw
serelaw
Throw hook.
Reel in.
Release Fish.
Throw hook
Reel in.
Release Fish.
Throw hook
Reel in
Release Fish.
lol
Reel in.
Release Fish.
Throw hook
Reel in.
Release Fish.
Throw hook
Reel in
Release Fish.
lol
#30
serelaw
serelaw
Fish,
Just teasing here.
Nothing personal.
Just teasing here.
Nothing personal.
#31
Fish
Fish
Yeah, I love good teasing!!!
#32
Fish
Fish
spring spacer.... What is that?
#33
Fish
Fish
You got a part number????
#34
Carscw
Carscw
Here is a couple good places for parts and info.
PerformanceRacingPartsbyHitch
On this one go down to the 3rd comment I think and it will tell you what to search for more info.
high rev kit 18 horse briggs
PerformanceRacingPartsbyHitch
On this one go down to the 3rd comment I think and it will tell you what to search for more info.
high rev kit 18 horse briggs
#35
Carscw
Carscw
Here are a couple of one I built last winter.
http://youtu.be/EwIyY5Nrcj4
http://youtu.be/X3CFL5jGkLc
http://youtu.be/nHypacgdFf0
This one is qualifying at the track
950hp
http://youtu.be/ejkSxnlqiBo
http://youtu.be/EwIyY5Nrcj4
http://youtu.be/X3CFL5jGkLc
http://youtu.be/nHypacgdFf0
This one is qualifying at the track
950hp
http://youtu.be/ejkSxnlqiBo
#36
serelaw
serelaw
Cool stuff
thanks
thanks
#37
Z
Zeroturner
Z
Zeroturner
I'm going to change how I engage and disengage the PTO as I've been doing it at full throttle for both, not knowing any better and I'm pretty sure this isn't addressed in the owners manual as I've read it cover to cover more than once - I hope I haven't caused my mower harm up to now...?
I'm at 112 hours.
And thanks for the advice on doing this the right way.
I'm at 112 hours.
And thanks for the advice on doing this the right way.
#38
DSepe
No biggie...not all manuals say this I engaged my lawn mower at full throttle for 25+ years...guess it didn't matter that much. I now engage at 1/2 throttle on new zero turn.
DSepe
I'm going to change how I engage and disengage the PTO as I've been doing it at full throttle for both, not knowing any better and I'm pretty sure this isn't addressed in the owners manual as I've read it cover to cover more than once - I hope I haven't caused my mower harm up to now...? I'm at 112 hours. And thanks for the advice on doing this the right way.
No biggie...not all manuals say this I engaged my lawn mower at full throttle for 25+ years...guess it didn't matter that much. I now engage at 1/2 throttle on new zero turn.
#39
djdicetn
At 100 hours you're just now broke in...you haven't caused any damage but throttling down for the PTO will just help your electric clutch last longer.
djdicetn
I'm going to change how I engage and disengage the PTO as I've been doing it at full throttle for both, not knowing any better and I'm pretty sure this isn't addressed in the owners manual as I've read it cover to cover more than once - I hope I haven't caused my mower harm up to now...?
I'm at 112 hours.
And thanks for the advice on doing this the right way.
At 100 hours you're just now broke in...you haven't caused any damage but throttling down for the PTO will just help your electric clutch last longer.
#41
djdicetn
djdicetn
Kinda like me when user Carscw warned me about transporting my Gravely at minimum throttle causing damage to my hydros(or engine).......I only have about 60 hours on mine and also hope I didn't hurt anything:0(Thanks guys for the reassurance.
I was worried...
#42
K
kwak
K
kwak
I asked my dealer about engaging the blades and he said to do it a full throttle so that is what I do. I am guilty of not looking that up in my owners manual so I am not sure what Scag recommends. As far as turning the machine off I usually throttle down before killing it.
#43
C
cecjack1
C
cecjack1
Having worked in aviation with piston engines and turbine engines, it has been for the longivity of piston engines to allow the engines to normalize from the extra heat generated in the working operation RPM by letting the lubricants (oil) disapate the built up heat from working and allowing the oil to disapate the extra heat. On Kubato ZTR Z331 manual suggests allowing engine to cool down for 2 minutes at a fast idle before shutting down. Allison Turbines learned the lesson years ago from bearing failures due to synthetic oil breakdown causing oil restrictions in the oil jets causing lack of lube to bearings. We had to cool down a full 2 minutes before shutting down. The oil temps would drop almost a 150 degress in that time. Makes sense to allow a piston engine the same previlage and adds to a longer lasting engine and transmission.
Cecil Jackson
Gravely 300 (2001 850 hours)
Kubota Z331 (2012 128 hours)
mowing 6 acres
Cecil Jackson
Gravely 300 (2001 850 hours)
Kubota Z331 (2012 128 hours)
mowing 6 acres
#44
gfp55
I have to thank you for joining this forum and for sharing your mind. I like your post. Keep it up. gfp55
gfp55
Having worked in aviation with piston engines and turbine engines, it has been for the longivity of piston engines to allow the engines to normalize from the extra heat generated in the working operation RPM by letting the lubricants (oil) disapate the built up heat from working and allowing the oil to disapate the extra heat. On Kubato ZTR Z331 manual suggests allowing engine to cool down for 2 minutes at a fast idle before shutting down. Allison Turbines learned the lesson years ago from bearing failures due to synthetic oil breakdown causing oil restrictions in the oil jets causing lack of lube to bearings. We had to cool down a full 2 minutes before shutting down. The oil temps would drop almost a 150 degress in that time. Makes sense to allow a piston engine the same previlage and adds to a longer lasting engine and transmission.
Cecil Jackson
Gravely 300 (2001 850 hours)
Kubota Z331 (2012 128 hours)
mowing 6 acres
I have to thank you for joining this forum and for sharing your mind. I like your post. Keep it up. gfp55
#45
C
cooper714
C
cooper714
I have a Kohler 25hp on my Exmark Lazer Z. If I don't idle down for at least 45 seconds before I turn it off it back fires. I know guys that never idle down their Kohlers and they all seem to need top end rebuilds after about 4 years of service. Mine lasted 8 years. Just coincedence ? I don't think so.
#46
Nwatson99
Nwatson99
I park my ZT and let it run at full throttle for right at a minute to blow away any higher heat from traveling off the engine, then I idle down for the engine to get that low soft running / idle sound before shutting off the engine.
#47
gfp55
Your smart for doing that. There is a thread on this forum with a guy with a Honda that blow a hole in the side of his engine with 2100 hours. He found out from a dealer he was shutting his engine down wrong because he was turn off the key at full throttle. He learned the hard way. More should read that thread and learn. "But thats just me"
gfp55
I have a Kohler 25hp on my Exmark Lazer Z. If I don't idle down for at least 45 seconds before I turn it off it back fires. I know guys that never idle down their Kohlers and they all seem to need top end rebuilds after about 4 years of service. Mine lasted 8 years. Just coincedence ? I don't think so.
Your smart for doing that. There is a thread on this forum with a guy with a Honda that blow a hole in the side of his engine with 2100 hours. He found out from a dealer he was shutting his engine down wrong because he was turn off the key at full throttle. He learned the hard way. More should read that thread and learn. "But thats just me"
#48
Carscw
Carscw
Past few weeks I just drive up on the trailer and shut it off. LOL
What I do is shut the blades off drive to the trailer then on to the trailer lower the deck then shut it off.
It has ran with no heavy load as I drive to the trailer.
I drop down to a idle then shut off all in one motion.
What I do is shut the blades off drive to the trailer then on to the trailer lower the deck then shut it off.
It has ran with no heavy load as I drive to the trailer.
I drop down to a idle then shut off all in one motion.
#49
Col F
Col F
Direct quote from the Briggs & Stratton Operator's Manual for the Model 310000 / 330000 series (19HP engine on Sears/Husqvarna), "How To Stop Engine - 1. With the throttle in the Fast position, turn the key switch to the Off position. Remove the key".
(Prior to reading this instruction for the engine on my newest machine, I always had reduced engines to low speed idle prior to shutting them off. For this new engine I have tried to remember to follow the B&S instruction, which I presume has some legitimate basis).
(Prior to reading this instruction for the engine on my newest machine, I always had reduced engines to low speed idle prior to shutting them off. For this new engine I have tried to remember to follow the B&S instruction, which I presume has some legitimate basis).
#50
A
arielredhunter2
I worked for International Harvester for about 10 years, and the reccomended procedure was to run the engine with no load for 5 minutes at just above an idle, before shutdown. Air cooled engine, same procedure, but at 1/2 maximum RPM. This ensures good airflow through the engine. The reason for the 5 minutes-no load is to stabilize engine temperatures before shutdown. Exhaust valve and exhaust chest areas are running much higher temperatures during high load operation. Driving the tractor (or truck) home to the barn, with the mower deck off, at 1/2 rpm would be considered part of the 5 minute regimen under IH Warrenty.
A
arielredhunter2
Thanks to everyone for your helpful/educational information.
I'm still learning...
I worked for International Harvester for about 10 years, and the reccomended procedure was to run the engine with no load for 5 minutes at just above an idle, before shutdown. Air cooled engine, same procedure, but at 1/2 maximum RPM. This ensures good airflow through the engine. The reason for the 5 minutes-no load is to stabilize engine temperatures before shutdown. Exhaust valve and exhaust chest areas are running much higher temperatures during high load operation. Driving the tractor (or truck) home to the barn, with the mower deck off, at 1/2 rpm would be considered part of the 5 minute regimen under IH Warrenty.
#51
gfp55
gfp55
I have reread all the manuals I have for machines with engines on them, Onan, Kohler, Tecumseh, Briggs & Stratton, Robin, etc. All say that to reduce engine speed before turning off engine. I know there are some manuals that say to turn off engine at full throttle, but I think I will reduce engine speed before turning off engine like I have for over 40 years anyways. "But thats just me"
#52
V
Valtex
V
Valtex
This is a timely question for us. We just purchased a 60" Hustler Super Z HD/ kawasaki engine for residential use on a bit of acreage. The dealer and the owners manual states to idle down, however, when speaking with a Hustler rep regarding another matter, he stated this is "old thinking" and idling down should NOT be done. We noticed the engine backfiring a bit after shutting down and wonder which method Kawasaki currently recommends? Have they not updated their owner manual as it does say to idle down.
#53
S
Shughes717
S
Shughes717
I used to idle down before shutting my Kawi fx series engine, but noticed it would backfire from time to time. My dealer instructed me to shut it off at full throttle. No more backfires.
#54
A
arielredhunter2
It's backfiring because it's hot. Under load, the exhaust valve is running a dull red. By running engine at 1/2 throttle, no load, it allows the engine to stabilize temperatures across the cylinder and head. Under load, the exhaust valve and ports run much hotter than the rest of the engine. Shutting off an engine that has been under load and is hot can easily lead to exhaust valve burning and sticking. Usually not right a way. After a year or two. You know, after the warrenty has run out.
A
arielredhunter2
I used to idle down before shutting my Kawi fx series engine, but noticed it would backfire from time to time. My dealer instructed me to shut it off at full throttle. No more backfires.
It's backfiring because it's hot. Under load, the exhaust valve is running a dull red. By running engine at 1/2 throttle, no load, it allows the engine to stabilize temperatures across the cylinder and head. Under load, the exhaust valve and ports run much hotter than the rest of the engine. Shutting off an engine that has been under load and is hot can easily lead to exhaust valve burning and sticking. Usually not right a way. After a year or two. You know, after the warrenty has run out.
#55
P
PJDudley
I throttle down now because when I would shut down my 19hp Troybilt after mowing a couple acre at full throttle it sometimes would diesel
during shutdown. So before shutting down I would lower the throttle to about 3/4 for a moment and then shut down. Since then I've purchased a
new 24hp Husqvarna and I do the same with it just for good practice. Certainly can't hurt.
Paul
P
PJDudley
Or, when you quit mowing, do you shut down the engine at full throttle and not concern yourself about it?
My old tractor style 46" deck, Craftsmen, powered by a 24 Hp, B & S Intek engine's manual never mentioned having to do this. So, I always left it going full blast when I killed the engine. I sold it to my next door neighbor with 350 hours on it and he is now running it with over 500 hours on it and he doesn't worry about shutting it down at idle.
My Toro manual says to idle all the way down, wait a minute and then turn off the engine.
What do you guys say?
I throttle down now because when I would shut down my 19hp Troybilt after mowing a couple acre at full throttle it sometimes would diesel
during shutdown. So before shutting down I would lower the throttle to about 3/4 for a moment and then shut down. Since then I've purchased a
new 24hp Husqvarna and I do the same with it just for good practice. Certainly can't hurt.
Paul
#56
S
Shughes717
It would still backfire after I let it idle for several minutes though. I know we have always let our diesel tractors idle before shutting them off after a day in the fields to let them cool off. Continued that practice with the mowers I have owned. The Kawi is the first one that backfired with me. It didn't make sense to me to shut it off at full throttle, and I couldn't find instructions on the proper shutoff procedure in the manual. It hasn't backfired since I have started shutting it off at 3/4 throttle. I hope I'm not damaging anything. I am counting on this mower to last me another 15 years or so.
S
Shughes717
It's backfiring because it's hot. Under load, the exhaust valve is running a dull red. By running engine at 1/2 throttle, no load, it allows the engine to stabilize temperatures across the cylinder and head. Under load, the exhaust valve and ports run much hotter than the rest of the engine. Shutting off an engine that has been under load and is hot can easily lead to exhaust valve burning and sticking. Usually not right a way. After a year or two. You know, after the warrenty has run out.
It would still backfire after I let it idle for several minutes though. I know we have always let our diesel tractors idle before shutting them off after a day in the fields to let them cool off. Continued that practice with the mowers I have owned. The Kawi is the first one that backfired with me. It didn't make sense to me to shut it off at full throttle, and I couldn't find instructions on the proper shutoff procedure in the manual. It hasn't backfired since I have started shutting it off at 3/4 throttle. I hope I'm not damaging anything. I am counting on this mower to last me another 15 years or so.
#57
A
arielredhunter2
A
arielredhunter2
I don't think you are going to hurt it the way you are doing it, as long as you run it for a few moments to stabilize temperture. Like driving it to the toolshed at 3/4 throttle ought to be long enough.It would still backfire after I let it idle for several minutes though. I know we have always let our diesel tractors idle before shutting them off after a day in the fields to let them cool off. Continued that practice with the mowers I have owned. The Kawi is the first one that backfired with me. It didn't make sense to me to shut it off at full throttle, and I couldn't find instructions on the proper shutoff procedure in the manual. It hasn't backfired since I have started shutting it off at 3/4 throttle. I hope I'm not damaging anything. I am counting on this mower to last me another 15 years or so.
#58
Carscw
Carscw
A mower engine cools down fastest when it is running at full throttle.
Driving around the yard to cool it off at 1/2 or 3/4 throttle is doing more harm then good to the engine and the hydros.
Driving around the yard to cool it off at 1/2 or 3/4 throttle is doing more harm then good to the engine and the hydros.
#59
A
arielredhunter2
Interesting thought. However, I've been doing just that for the past 30 years with my Cub Cadet 147 Hydro with no ill effects. Engine has been honed and re-ringed once. I don't believe in boring side valve engines. Causes more heat distortion on the exhaust valve side.
A
arielredhunter2
A mower engine cools down fastest when it is running at full throttle.
Driving around the yard to cool it off at 1/2 or 3/4 throttle is doing more harm then good to the engine and the hydros.
Interesting thought. However, I've been doing just that for the past 30 years with my Cub Cadet 147 Hydro with no ill effects. Engine has been honed and re-ringed once. I don't believe in boring side valve engines. Causes more heat distortion on the exhaust valve side.
#60
S
Shughes717
S
Shughes717
I don't like the sound the hydros make when moving at less than full throttle. It whines more. I don't move it unless I'm at full throttle. There are so many different opinions on the proper way to shut the engine off. It is very confusing.
#61
Z
zmister11
Yeah i do the same
Z
zmister11
I don't like the sound the hydros make when moving at less than full throttle. It whines more. I don't move it unless I'm at full throttle. There are so many different opinions on the proper way to shut the engine off. It is very confusing.
Yeah i do the same
#62
Elendil
Elendil
Interesting thread.
Just to throw in my 2 cents: Just got done reading my owners manual for my new Z723KH. Here is a direct quote: "After slowing the engine to half speed, turn the key switch to the OFF position"
There is also an additional note at the bottom of the same page: "Place the throttle control lever in the half speed position to help prevent the engine from backfiring before stopping the engine"
Just to throw in my 2 cents: Just got done reading my owners manual for my new Z723KH. Here is a direct quote: "After slowing the engine to half speed, turn the key switch to the OFF position"
There is also an additional note at the bottom of the same page: "Place the throttle control lever in the half speed position to help prevent the engine from backfiring before stopping the engine"
#63
exotion
exotion
I think its all a bunch of hullabulloo :/ just turn the machine off speed doesn't matter. What you don't want is to turn the machine then start it back up within a few seconds
#64
A
arielredhunter2
We are all welcome to think whatever we wish. This makes as much sense as starting your car in the winter time, leaving the driveway, and accelerating to 70 mph with a cold engine on a 20 degree morning. An engine is composed of a group of different metals, all with different rates of contraction and expansion.
A
arielredhunter2
I think its all a bunch of hullabulloo :/ just turn the machine off speed doesn't matter. What you don't want is to turn the machine then start it back up within a few seconds
We are all welcome to think whatever we wish. This makes as much sense as starting your car in the winter time, leaving the driveway, and accelerating to 70 mph with a cold engine on a 20 degree morning. An engine is composed of a group of different metals, all with different rates of contraction and expansion.
#65
LazerZLandscaping
LazerZLandscaping
I just shut the mower off and then bring the lever all the way down
#66
D
Diwali
D
Diwali
Yes. I have no idea what the manual says but my Craftsman LT2000 backfires loudly if I don’t. Sometimes it does it even with the throttle at minimum but considerably less often than when I shut off at a higher throttle.
#67
G
Gord Baker
It is important to give Air Cooled and Liquid cooled mower engines a short cool down period and wise to idle down the engine before shutting off the Ignition.
This prevents raw gas from washing lubricant from cylinder walls and weeping into the crank case. If you notice, the engine makes several revs after Ignition is turned off, sucking in raw fuel. The electrical shutoff does not prevent this from happening in most if not all cases.
G
Gord Baker
Or, when you quit mowing, do you shut down the engine at full throttle and not concern yourself about it?
My old tractor style 46" deck, Craftsmen, powered by a 24 Hp, B & S Intek engine's manual never mentioned having to do this. So, I always left it going full blast when I killed the engine. I sold it to my next door neighbor with 350 hours on it and he is now running it with over 500 hours on it and he doesn't worry about shutting it down at idle.
My Toro manual says to idle all the way down, wait a minute and then turn off the engine.
What do you guys say?
It is important to give Air Cooled and Liquid cooled mower engines a short cool down period and wise to idle down the engine before shutting off the Ignition.
This prevents raw gas from washing lubricant from cylinder walls and weeping into the crank case. If you notice, the engine makes several revs after Ignition is turned off, sucking in raw fuel. The electrical shutoff does not prevent this from happening in most if not all cases.
#68
R
rascal1
R
rascal1
Letting the engine idle cools down the exhaust valve. The only cooling the exhaust valve head gets is when its closed on the power stroke when under load. At idle it has longer contact with valve seat transferring heat.
#69
M
Michiglenn
I agree with this. Without ignition to fire the mixture, the cylinder walls and rings are being washed with raw fuel (unless fuel injected). This is not a good practice for carbureted engines. Letting the engine idle for a couple minutes or so will cool the exhaust valves and draw very little raw gas when shut down.
M
Michiglenn
It is important to give Air Cooled and Liquid cooled mower engines a short cool down period and wise to idle down the engine before shutting off the Ignition.
This prevents raw gas from washing lubricant from cylinder walls and weeping into the crank case. If you notice, the engine makes several revs after Ignition is turned off, sucking in raw fuel. The electrical shutoff does not prevent this from happening in most if not all cases.
I agree with this. Without ignition to fire the mixture, the cylinder walls and rings are being washed with raw fuel (unless fuel injected). This is not a good practice for carbureted engines. Letting the engine idle for a couple minutes or so will cool the exhaust valves and draw very little raw gas when shut down.
#70
Rob47
Rob47
For me it is a habit to idle the engine down before shut-down - it represents the reverse of starting an engine at full throttle just because of momentary delay of oil delivery to the bearings on an automotive engine. So in this case it is meaningless.
The other reason I will idle it down is one of determining where new bearing noises might be coming from. Since there is a number of pulleys on riding mowers that control and tension belts, it will allow me to HEAR any new noise that has developed once the engine has slowed down to an idle. Many owners are not aware of bearing noise until it starts to scream or seize. In some instances this can also tear up a belt. I will also periodically remove the deck drive belt(s) to hand spin the spindles to see if they are generating noise. I will choose to replace the bearings in the spindles rather than buy the whole spindle assembly from the dealer. If delayed, the bearings will seize and tear up the spindle casting and force the replacement of the assembly.
If you are not a mechanic and have a shop with adequate tools, then this procedure is not ideal - just pay the money and buy the whole spindle assembly.
The other reason I will idle it down is one of determining where new bearing noises might be coming from. Since there is a number of pulleys on riding mowers that control and tension belts, it will allow me to HEAR any new noise that has developed once the engine has slowed down to an idle. Many owners are not aware of bearing noise until it starts to scream or seize. In some instances this can also tear up a belt. I will also periodically remove the deck drive belt(s) to hand spin the spindles to see if they are generating noise. I will choose to replace the bearings in the spindles rather than buy the whole spindle assembly from the dealer. If delayed, the bearings will seize and tear up the spindle casting and force the replacement of the assembly.
If you are not a mechanic and have a shop with adequate tools, then this procedure is not ideal - just pay the money and buy the whole spindle assembly.
#71
P
patrick_g
P
patrick_g
Is there a downside to throttling down to idle before shutting down? Needed or not it doesn't hurt and could help. Letting it idle for a little cool down before shutting off the ignition is IMHO not going to hurt and likely will be kinder and gentler to the engine.
Oh, and by the way... Hi, I'm Patrick. New guy on this forum and fairly new to ride-on mowers. (previously just used brush hog o Kubota compact tractor 39 HP at PTO.)
Oh, and by the way... Hi, I'm Patrick. New guy on this forum and fairly new to ride-on mowers. (previously just used brush hog o Kubota compact tractor 39 HP at PTO.)
#72
G
GrassFire
I know some claim the engine is actually hotter when idled down because the ventilation has been reduced. Supposedly if you shut it off at full throttle, you're at maximum cooling so it doesn't have the chance to build heat by reducing the rpm's. Seems odd but I have read it before.
I started in 1999. I have always idled down before shutting off and I start at idle speed. I engage my PTO at idle and disengage at idle, also. Never had an engine issue to date. But I also sell my equipment with less than 1000 hours.
G
GrassFire
Is there a downside to throttling down to idle before shutting down? Needed or not it doesn't hurt and could help. Letting it idle for a little cool down before shutting off the ignition is IMHO not going to hurt and likely will be kinder and gentler to the engine.
Oh, and by the way... Hi, I'm Patrick. New guy on this forum and fairly new to ride-on mowers. (previously just used brush hog o Kubota compact tractor 39 HP at PTO.)
I know some claim the engine is actually hotter when idled down because the ventilation has been reduced. Supposedly if you shut it off at full throttle, you're at maximum cooling so it doesn't have the chance to build heat by reducing the rpm's. Seems odd but I have read it before.
I started in 1999. I have always idled down before shutting off and I start at idle speed. I engage my PTO at idle and disengage at idle, also. Never had an engine issue to date. But I also sell my equipment with less than 1000 hours.
#73
Ronno6
Ronno6
If I remember correctly, my Hustler manual says to engage PTO at 2/3 throttle or so,
and idle down prior to disengaging.
Seems like shutting off the engine at idle is a logical step afterwards.
and idle down prior to disengaging.
Seems like shutting off the engine at idle is a logical step afterwards.
#74
E
efred
E
efred
I was told by a tractor mechanic (I'm a farmer) to run engine at about 1/3 throttle, not 1/2, not bottom idle; at about 1/3 idle, the engine will cool down most efficiently (enough fan cooling, not making a lot of heat), and then shutting off after about a minute works best.
For my mower, a '98 CC 2165, letting it idle at about 1/3 throttle for about a minute will shut off fine. If I shut it off at full throttle, it will backfire. My best friend, who has an '06 Dixon, has to shut his off at full throttle, or it will backfire at anything less. So, in general, follow your model's manual for shutdown.
For my mower, a '98 CC 2165, letting it idle at about 1/3 throttle for about a minute will shut off fine. If I shut it off at full throttle, it will backfire. My best friend, who has an '06 Dixon, has to shut his off at full throttle, or it will backfire at anything less. So, in general, follow your model's manual for shutdown.
#75
R
rrodger9
R
rrodger9
Per my owner's manual, I put my CV25s at half throttle before shutting it off. This is to avoid backfiring. I also throttle it down before engaging the pto clutch. This is to help preserve the deck belt and clutch.
#76
C
CalgaryPT
LOL. Agreed.
But my teenager wouldn't. Apparently"cool" people rev their engines before turning them off.
No wonder I am a social failure. This forum really is helpful.
C
CalgaryPT
Absolutely, at least 30 seconds at low idle before shutting down. I can't recall hearing or seeing anyone press their vehicle gas pedal to the floor and holding it before switching the the key to off.
LOL. Agreed.
But my teenager wouldn't. Apparently"cool" people rev their engines before turning them off.
No wonder I am a social failure. This forum really is helpful.
#77
H
huck18
H
huck18
my ferris 21hp kawasaki mower wants to be shut down at full throttle or it will backfire when I shut it down after lowering the the throttle, called the dealership and was told to shut it down at full throttle.
#78
P
patrick_g
P
patrick_g
There is an obvious benefit to letting an engine cool down some before shut down. Heat stored in high temp metal components of the engine tends to "fry" the lubricating oil a little at each full temp shutdown. A little cool down before shut down reduces that significantly and helps preserve the high tech additives in the oil to the benefit of engine's longevity. Unfortunately some folks experience backfiring if they attempt a low RPM shutdown. Still there are concerns regarding unburned fuel if engines are shut down at high throttle settings.
I have a plethora of small gasoline engines in such devices as generators, self propelled DR string mower/trimmer, a Weed Eater string trimmer, 5-6 chain saws, and on and on. It is my practice to run a device at a low throttle setting for cool down and then turn off the fuel and let the engine die from fuel starvation. No excess fuel washing lubrication off the piston and cylinder and no fuel left in the carb to cause varnish and plug things up if the device isn't run for a while.
My 46 inch swath Cub Cadet ride-on mower is happy to be shut off after a cool down at reduced RPM and does not backfire. If backfire was a problem for me I would consider shutting the fuel off and letting the engine run at cool down RPM until it ran out of fuel.
A cool down period will not double your engine life but it will tend to increase it.
I have a plethora of small gasoline engines in such devices as generators, self propelled DR string mower/trimmer, a Weed Eater string trimmer, 5-6 chain saws, and on and on. It is my practice to run a device at a low throttle setting for cool down and then turn off the fuel and let the engine die from fuel starvation. No excess fuel washing lubrication off the piston and cylinder and no fuel left in the carb to cause varnish and plug things up if the device isn't run for a while.
My 46 inch swath Cub Cadet ride-on mower is happy to be shut off after a cool down at reduced RPM and does not backfire. If backfire was a problem for me I would consider shutting the fuel off and letting the engine run at cool down RPM until it ran out of fuel.
A cool down period will not double your engine life but it will tend to increase it.
#79
B
broo
B
broo
My operator manual for Toro Timecutter tells me that engine startup, turn off, and both PTO engaging and disengaging should all be done at full throttle.
Makes you wonder why they bothered installing a throttle control at all.
I still idle it a bit before turning it off out of habit.
Makes you wonder why they bothered installing a throttle control at all.
I still idle it a bit before turning it off out of habit.
#80
mhavanti
mhavanti
Its all those folks that kill engines at full throttle that engine re-manufacturers and for that matter, engine manufacturers love. Full throttle shut off does a few things to your engine. Allows a nice lean condition as the engine is slowing once the ignition is switched off as long as the anti-backfire solenoid is working. For those that either don't have a working solenoid or the solenoid has been disabled by the plunger shortened, there will be a full rich mode. Now, full rich does help cool the engine I'll give you that. Fuel that isn't burnt also cleans the lubricating facilities from the valve guide, cylinder, piston skirt and rings. The fuel that gets past the rings goes where?
We can go on and on from a machine shop perspective and thank you for continuing to shut down with WOT. lmbo. At any length, if the manufacturer is telling you to shut down WOT, then you bought from the wrong manufacturer. Brand loyalty used to come from longevity of products, ease of use, manufacturer truth, etc.
What has the world come to?
Max
We can go on and on from a machine shop perspective and thank you for continuing to shut down with WOT. lmbo. At any length, if the manufacturer is telling you to shut down WOT, then you bought from the wrong manufacturer. Brand loyalty used to come from longevity of products, ease of use, manufacturer truth, etc.
What has the world come to?
Max
#81
E
EricG1793
E
EricG1793
I always idle down before turning the engine off if there is a throttle. If I've been mowing, idle a couple minutes before turning off.
On my 2004 Cub LT1018 with a Kohler Command and grandfather's 2007 Craftsman LT2000 with a B&S Intek, if I simply turn the engine off right after turning the blades off, they'll often backfire. I've never tried immediately turning off at full throttle after mowing, though. Likewise, starting the engine within a minute or two after it's been mowing often causes backfires.
On my 2004 Cub LT1018 with a Kohler Command and grandfather's 2007 Craftsman LT2000 with a B&S Intek, if I simply turn the engine off right after turning the blades off, they'll often backfire. I've never tried immediately turning off at full throttle after mowing, though. Likewise, starting the engine within a minute or two after it's been mowing often causes backfires.
#82
G
greggn
G
greggn
I let the engine idle at a fast idle for a bit as well as a warmup at 1/3-1/2 throttle at first.
#83
1
1RB2534
1
1RB2534
Got an email today on this thread, looks like it's an old ongoing one. Or at least probably every time an email reminder goes out on it.
I remember in the Army they told us we had to idle all our diesel equipment at least 5 mins before shutting off. But I surmise diesels get a bit hotter than gas engines.
In any case many of the briggs push mowers you buy now days don't even have a throttle. You prime the button and pull the rope while holding the idiot shut off safety lever against the handle. When it cranks it goes immediately to wide open. When you get done you let go of the idiot shut off and it immediately brakes to a dead stop. Done deal, it's kinda mandated by government, lawyers and or insurance companies. Same as the Ethanol they put in our gas that destroyed my chain saw fuel lines till I paid more for ethanol free fuel in the can at Walmart. After all that's what we pay taxes right?
So do I idle down, well yes when I'm not letting go of the idiot lever. I figure the engine feels a bit like me on a hot day and needs to walk it off after huffing and puffing. But then what does an old fart like me know anyhow.
I remember in the Army they told us we had to idle all our diesel equipment at least 5 mins before shutting off. But I surmise diesels get a bit hotter than gas engines.
In any case many of the briggs push mowers you buy now days don't even have a throttle. You prime the button and pull the rope while holding the idiot shut off safety lever against the handle. When it cranks it goes immediately to wide open. When you get done you let go of the idiot shut off and it immediately brakes to a dead stop. Done deal, it's kinda mandated by government, lawyers and or insurance companies. Same as the Ethanol they put in our gas that destroyed my chain saw fuel lines till I paid more for ethanol free fuel in the can at Walmart. After all that's what we pay taxes right?
So do I idle down, well yes when I'm not letting go of the idiot lever. I figure the engine feels a bit like me on a hot day and needs to walk it off after huffing and puffing. But then what does an old fart like me know anyhow.
#84
T
Tom S. in Tn.
T
Tom S. in Tn.
My old Tecumseh does not have a fuel shut off solenoid and keeps running and makes clattering noise unless the throttle is at dead idle.
Had a Briggs that would afterfire like a rifle shot after the engine shut off unless let run at idle for a couple minutes before shut down. If the crank did not stop turning after the key was turned off, it pulled fuel in and unburned into the muffler.
Had a Briggs that would afterfire like a rifle shot after the engine shut off unless let run at idle for a couple minutes before shut down. If the crank did not stop turning after the key was turned off, it pulled fuel in and unburned into the muffler.
#85
W
whiteshu
W
whiteshu
My John Deere 322 has a Janmar three cylinder engine. If I try to shut down at full throttle it will diesel. This could hurt the engine. So I idle down to the lowest rpm, an then shutoff. My John Deere X738 has a fuel injected Kawasaki engine. The manual instructs: Go to half throttle, then shut off.
#86
S
snesler
Yes I do, you can ask any general aviation pilot the importance of proper warming and cooling of a piston air cooled engine and they will tell you to always slowly cool the engine and avoid what is called shock cooling, going from hot to cold too quickly. Full power is not applied until proper engine oil temperature is reached.
The next time you see a piston engine helicopter land, notice how long the the pilot remains in idle prior to engine shut down, usually one - two minutes allowing the engine to slowly cool.
An air cooled engine is an air cooled engine regardless of the application, warm and cool slowly is best practice.
S
snesler
Or, when you quit mowing, do you shut down the engine at full throttle and not concern yourself about it?
My old tractor style 46" deck, Craftsmen, powered by a 24 Hp, B & S Intek engine's manual never mentioned having to do this. So, I always left it going full blast when I killed the engine. I sold it to my next door neighbor with 350 hours on it and he is now running it with over 500 hours on it and he doesn't worry about shutting it down at idle.
My Toro manual says to idle all the way down, wait a minute and then turn off the engine.
What do you guys say?
Yes I do, you can ask any general aviation pilot the importance of proper warming and cooling of a piston air cooled engine and they will tell you to always slowly cool the engine and avoid what is called shock cooling, going from hot to cold too quickly. Full power is not applied until proper engine oil temperature is reached.
The next time you see a piston engine helicopter land, notice how long the the pilot remains in idle prior to engine shut down, usually one - two minutes allowing the engine to slowly cool.
An air cooled engine is an air cooled engine regardless of the application, warm and cool slowly is best practice.
#87
BlazNT
Except for a lawnmower engine gets hotter when you lower the idle. The fan slows and the engine heats up.
BlazNT
Yes I do, you can ask any general aviation pilot the importance of proper warming and cooling of a piston air cooled engine and they will tell you to always slowly cool the engine and avoid what is called shock cooling, going from hot to cold too quickly. Full power is not applied until proper engine oil temperature is reached.
The next time you see a piston engine helicopter land, notice how long the the pilot remains in idle prior to engine shut down, usually one - two minutes allowing the engine to slowly cool.
An air cooled engine is an air cooled engine regardless of the application, warm and cool slowly is best practice.
Except for a lawnmower engine gets hotter when you lower the idle. The fan slows and the engine heats up.
#88
7394
Max- MY Toro Dealer told me to start & stop my Kawasaki engine at FULL throttle. :thumbdown: I showed him the manual I got for the engine from Kawasaki, & it states to start at idle & let warm up, then go to about 1/2 throttle before I engage blades, then wfo.
And shut down is stated to be idled down & then shut off. He called out the head mechanic & showed him what the book said. Head wrench said, I NEVER heard of that. (obviously, not a big reader)
Well I did. But I have also been doing it on all the mowers I had in the past as well.
7394
Its all those folks that kill engines at full throttle that engine re-manufacturers and for that matter, engine manufacturers love. Full throttle shut off does a few things to your engine. Allows a nice lean condition as the engine is slowing once the ignition is switched off as long as the anti-backfire solenoid is working. For those that either don't have a working solenoid or the solenoid has been disabled by the plunger shortened, there will be a full rich mode. Now, full rich does help cool the engine I'll give you that. Fuel that isn't burnt also cleans the lubricating facilities from the valve guide, cylinder, piston skirt and rings. The fuel that gets past the rings goes where?
We can go on and on from a machine shop perspective and thank you for continuing to shut down with WOT. lmbo. At any length, if the manufacturer is telling you to shut down WOT, then you bought from the wrong manufacturer. Brand loyalty used to come from longevity of products, ease of use, manufacturer truth, etc.
What has the world come to?
Max
Max- MY Toro Dealer told me to start & stop my Kawasaki engine at FULL throttle. :thumbdown: I showed him the manual I got for the engine from Kawasaki, & it states to start at idle & let warm up, then go to about 1/2 throttle before I engage blades, then wfo.
And shut down is stated to be idled down & then shut off. He called out the head mechanic & showed him what the book said. Head wrench said, I NEVER heard of that. (obviously, not a big reader)
Well I did. But I have also been doing it on all the mowers I had in the past as well.
#89
cpurvis
cpurvis
I can't imagine any engine which would benefit from shutting down at full throttle, especially gas engines.
#90
upupandaway
upupandaway
It says in the Stihl manual to idle for a min or 2 after hard work to cool down = (moving air and all) vs kill at high when everything is hotty hot.
Given this is from my 80's blower manual.
That's my 2,000Venezuelan Bolívar FWIW
Given this is from my 80's blower manual.
That's my 2,000Venezuelan Bolívar FWIW
#91
J
Johnbt
J
Johnbt
I have a 2015 Toro MX-5050 with a 24 hp Kohler 7000. The manual says to use between half and full throttle. Here's the quote...
"1. Disengage the blades by moving the blade control
switch to Off.
2. Move the throttle lever to between the half and full
throttle position.
3. Turn the ignition key to Off and remove the key."
I also have a like-new 2016 Deere X380 that I bought for my 85-year-old uncle last year; but he can no longer mow so he gave it back. The engine is a 22 hp Kawasaki FS651V. The manual says to lower the throttle to 1/2 for several seconds and then switch it off.
"1. Disengage the blades by moving the blade control
switch to Off.
2. Move the throttle lever to between the half and full
throttle position.
3. Turn the ignition key to Off and remove the key."
I also have a like-new 2016 Deere X380 that I bought for my 85-year-old uncle last year; but he can no longer mow so he gave it back. The engine is a 22 hp Kawasaki FS651V. The manual says to lower the throttle to 1/2 for several seconds and then switch it off.
#92
cpurvis
That's odd, because here's what Kawasaki has to say about it the FR651V:
cpurvis
I have a 2015 Toro MX-5050 with a 24 hp Kohler 7000. The manual says to use between half and full throttle. Here's the quote...
"1. Disengage the blades by moving the blade control
switch to Off.
2. Move the throttle lever to between the half and full
throttle position.
3. Turn the ignition key to Off and remove the key."
I also have a like-new 2016 Deere X380 that I bought for my 85-year-old uncle last year; but he can no longer mow so he gave it back. The engine is a 22 hp Kawasaki FS651V. The manual says to lower the throttle to 1/2 for several seconds and then switch it off.
That's odd, because here's what Kawasaki has to say about it the FR651V:
Attachments
#93
7394
That's the manual I have, & when I showed my Toro Dealer that Kawasaki states clearly to go to idle before shut down. They couldn't believe that. (narrow minds).
7394
That's odd, because here's what Kawasaki has to say about it the FR651V:
That's the manual I have, & when I showed my Toro Dealer that Kawasaki states clearly to go to idle before shut down. They couldn't believe that. (narrow minds).
#94
J
Johnbt
J
Johnbt
Beats me. Maybe they build them differently for Deere. Maybe a different fuel shutoff. This is my first Deere and first Kawasaki.
Hmm, and my iphone loaded the pics sideways.
Hmm, and my iphone loaded the pics sideways.
#95
M
Michiglenn
M
Michiglenn
Last night I checked my Kawasaki Z465 cylinder head temperature with my non-contact heat sensor gun to satisfy my curiosity. Immediately after mowing it was 215-220 degrees. I let it idle for about 2 minutes and it was reading about 190-195. The manual gives this as operating advice:
#96
J
Johnbt
J
Johnbt
Looking at the Kawa manual and my Deere manual,
Kawa says to:
”To warm up the engine, run it for 3 to 5 minutes
with the throttle lever in the same load position
.halfway) before putting the equipment under load"
The Deere manual says to"
"Run engine at half throttle for 30-60 seconds to allow warm-up before operating"
"IMPORTANT: Avoid damage! Unnecessary engine idling may cause engine damage." They list overheating, carbon and poor performance.
Kawa says to:
”To warm up the engine, run it for 3 to 5 minutes
with the throttle lever in the same load position
.halfway) before putting the equipment under load"
The Deere manual says to"
"Run engine at half throttle for 30-60 seconds to allow warm-up before operating"
"IMPORTANT: Avoid damage! Unnecessary engine idling may cause engine damage." They list overheating, carbon and poor performance.
#97
7394
7394
I think Kawasaki has a clue to what's best, they did make the engines after all.
#98
J
Johnbt
J
Johnbt
You would think that. Otoh, John Deere buys the engines and provides the warranty on them and the warranty service. So I've been told. Maybe Deere is changing something on the engines they buy or maybe Deere thinks or knows that the instructions in the Deere manual are saving them tons of warranty dollars. I certainly don't know anything about John Deere, but they seem to be very successful and on the ball about making money.
This thread on Lawnsite has the same info on the warranty that I've been told. Post #41...
www.lawnsite.com/threads/problem-with-2016-kawasaki-fx850v-engine.460750/page-5
"A while back, I had a long casual conversation with a really nice Kawasaki Factory Rep ...he flat out stated that they sell engines to John Deere by the pallet ... and once they do ... ALL warranty work must be approved and performed by the dealer ... no exceptions."
__________
I'll keep mowing with the Toro ztr - great cut, fast and easy too. I put Gator G5's on the X380 and will see if it can earn its keep chopping leaves or at least blowing them into the woods. I really don't have much use for a mower with a steering wheel. It's so 20th century. :laughing:
This thread on Lawnsite has the same info on the warranty that I've been told. Post #41...
www.lawnsite.com/threads/problem-with-2016-kawasaki-fx850v-engine.460750/page-5
"A while back, I had a long casual conversation with a really nice Kawasaki Factory Rep ...he flat out stated that they sell engines to John Deere by the pallet ... and once they do ... ALL warranty work must be approved and performed by the dealer ... no exceptions."
__________
I'll keep mowing with the Toro ztr - great cut, fast and easy too. I put Gator G5's on the X380 and will see if it can earn its keep chopping leaves or at least blowing them into the woods. I really don't have much use for a mower with a steering wheel. It's so 20th century. :laughing:
#99
7394
7394
Well I'll tell you what my local Toro Dealer states, is that they must get approval from Kawasaki, Kohler or Briggs before then can do any serious warranty issues.
Like they want to see evidence before they will replace a complete engine fore example.
Like they want to see evidence before they will replace a complete engine fore example.
#100
J
Johnbt
J
Johnbt
That's what my Toro/Scag dealer says, too.
What Deere seems to be doing is buying the engines and assuming responsibility for ALL the warranty work. They get a big price break on the purchase price for providing the warranty on the engines because Kawa doesn't have to spend a penny on repairs in the future.
Like I said, this is my first Deere anything, so I'm learning the system.
What Deere seems to be doing is buying the engines and assuming responsibility for ALL the warranty work. They get a big price break on the purchase price for providing the warranty on the engines because Kawa doesn't have to spend a penny on repairs in the future.
Like I said, this is my first Deere anything, so I'm learning the system.
#101
7394
Interesting, sounds logical about Deere buying the engines & covering the warranty. That would seem to give them a much better price.
7394
That's what my Toro/Scag dealer says, too.
What Deere seems to be doing is buying the engines and assuming responsibility for ALL the warranty work. They get a big price break on the purchase price for providing the warranty on the engines because Kawa doesn't have to spend a penny on repairs in the future.
Like I said, this is my first Deere anything, so I'm learning the system.
Interesting, sounds logical about Deere buying the engines & covering the warranty. That would seem to give them a much better price.
#102
R
ron217
Let me ask then, Do you continue to keep you right foot on the gas peddle in you car or truck when you put it away or do you release it and thus allow the engine to go to an idle?
R
ron217
Or, when you quit mowing, do you shut down the engine at full throttle and not concern yourself about it?
My old tractor style 46" deck, Craftsmen, powered by a 24 Hp, B & S Intek engine's manual never mentioned having to do this. So, I always left it going full blast when I killed the engine. I sold it to my next door neighbor with 350 hours on it and he is now running it with over 500 hours on it and he doesn't worry about shutting it down at idle.
My Toro manual says to idle all the way down, wait a minute and then turn off the engine.
What do you guys say?
Let me ask then, Do you continue to keep you right foot on the gas peddle in you car or truck when you put it away or do you release it and thus allow the engine to go to an idle?
#103
C
cruzenmike
C
cruzenmike
In my experience, at least on newer machines (15 yrs old and less) the manufacturer of the engine or the equipment will give guidance on this. There are "logical" reasons to do one thing vs the other, but I am of the opinion that the manufacturer's recommendation is the way to go since they are the ones who have (for the most part) designed, engineered, tested and warrantied the engine.
Now, I personally like to run my engines dry by using the fuel shut off. On the push mowers they are running at full rpm until they die out. On my v-twins I would shut the fuel off and run at idle until it died out. Now I just shut it down at half throttle (as recommended by the engine manufacturer) and turn off the fuel supply. I also run non-ethanol fuel 100% of the time so I am not as concerned about the fuel sitting in the carb/bowl in-between uses. I do ALWAYS run all of my equipment dry at the end of the season.
Not to go off on a tangent, but I have also seen where people have installed a small pep-cock at the bottom of their carb bowl to run out any fuel after they had shut their equipment down.
I guess you have to think about what happens inside of the combustion chamber when the engine suddenly loses spark but has been fed the maximum amount of fuel. I wouldn't know if this stops the engine in an enriched or lean condition that would make for later starts easier/harder or if it would cause smoking at startup.
Now, I personally like to run my engines dry by using the fuel shut off. On the push mowers they are running at full rpm until they die out. On my v-twins I would shut the fuel off and run at idle until it died out. Now I just shut it down at half throttle (as recommended by the engine manufacturer) and turn off the fuel supply. I also run non-ethanol fuel 100% of the time so I am not as concerned about the fuel sitting in the carb/bowl in-between uses. I do ALWAYS run all of my equipment dry at the end of the season.
Not to go off on a tangent, but I have also seen where people have installed a small pep-cock at the bottom of their carb bowl to run out any fuel after they had shut their equipment down.
I guess you have to think about what happens inside of the combustion chamber when the engine suddenly loses spark but has been fed the maximum amount of fuel. I wouldn't know if this stops the engine in an enriched or lean condition that would make for later starts easier/harder or if it would cause smoking at startup.
#104
T
txmowman
T
txmowman
Toro manual procedure is to allow the muffler to cool somewhat to prevent after bang. Even with a fuel solenoid, there is still fuel in the emulsion tube of the carburetor that can be drawn into a hot muffler and igniting. Bottom line, shutting the engine off at high or low idle will not harm the engine.