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valve lash

#1

G

gregjo1948

Working on a Briggs single cylinder 17.5 hp. I need to know what to set the valve lash at. thanks, gregjo1948


#2

I

ILENGINE

Assuming OHV engine and not flathead the setting would be .004-.006 for both valves.


#3

G

gregjo1948

Thanks ilengine. It is an overhead valve engine. Did Briggs even make a 17.5 hp flathead? gregjo1948


#4

I

ILENGINE

In theory I am sure they did. Could of just been a relabeled 16 or 17 hp engine. There was a lot of that several years ago. I saw a 40 series opposed twin briggs several years ago with a 12.5 sticker on the housing. that was normally a 16 if I remember correctly.


#5

T

Tinkerer200

Actually the 40 series opposed twin started out as a 12.5 hp. It grew to a 14 hp then finally a 16 hp. At the end of the run of 42 and 46 opposed twins several different stickers were stuck on the remaining engines, lower than their original rating and generally ending in .5. All the other remaining flat head stock was done similar.

While Illinois is a pro and his settings will work, actual spec is .003"- .005" for the Intake and .005"- .007" for the exhaust. I go for the min. on the Intake for compression release reasons.

I can send you detailed instructions on setting the valves AND a Service Manual IF you like. Address below, put in proper format and remind me engine model number and what you want.

Walt Conner
wconner5 at frontier dot com


#6

PTmowerMech

PTmowerMech

I have an 11 or 11.5hp opposed twin out there somewhere. But with everyone wanting 20+hp's now, I haven't bothered with it.


#7

I

ILENGINE

PTmowerMech said:
I have an 11 or 11.5hp opposed twin out there somewhere. But with everyone wanting 20+hp's now, I haven't bothered with it.
Click to expand...

And that is a story for another time. Everybody knows horsepower sells, but why does it now take 25 hp to run a mower that used to only take 10 hp years ago.


#8

PTmowerMech

PTmowerMech

Has anyone tried to put a 10hp on a zero turn that came with a 25? I wonder if it would last very long. I'm sure with the right carburetor mixture , it would turn the blades fine.


#9

7394

7394

A Zero has a lot more load on the engine from the 2 pumps & super fast blade tip speeds. I think the makers know what power a Z needs.


#10

cpurvis

cpurvis

Plus ZT's have upped the mowing width and mowing speed.


#11

G

gregjo1948

If you put 10hp on a full grown Ferris Z, it would have trouble turning the blades without mowing grass. These machines spin their blades extremely fast, travel over 10mph while mowing uphill, and weigh upwards of 3/4 of a ton. 10hp will work OK on a YT/GT with a 42" deck weighing 300lbs. mowing at 4mph but it'll take all day to mow a lawn that a 61" Ferris will do in 2 hours. Until you operate a Ferris with the totally independent suspension and mow, what used to be hay fields/pastures, you can't imagine how much better it rides than a YT/GT. YT/GT machines are good enough for a small city lawn and are handy to pull around a little yard cart but if you want to get large or many lawns mowed, a Z with bigger hp is the way to go. 10 hp engines won't work worth a hoot and won't last on a Z. That's why the manufacturers install the big hp twins, triples, and even diesel engines. Sorry about my rant but, 10 hp on a Z just struck me wrong!!!!


#12

G

gregjo1948

PTmowerMech said:
I have an 11 or 11.5hp opposed twin out there somewhere. But with everyone wanting 20+hp's now, I haven't bothered with it.
Click to expand...

Is it an opposed twin or a V twin?


#13

I

ILENGINE

The point I was trying to make was back about 30 years ago the garden tractors with 42-48 in decks were 10-16 hp gear or hydrostat. Even the Case 446 which was made by ingersoll was all hydraulic drive, and had a 4 foot tiller or rough cut mower available that were hydraulic drive like a skid steer attachment, And they were 16 hp, then sometimes around the early 2000's is when the HP took off and everything got bigger about the same time that EPA tier 1 came into play. I was working on 7.5 hp push mower engines fitted on 22 inch push mower that were just 5 years prior were 3.75 hp engines.

Some of the Z turns with 25-27 hp engines I have worked on the last few years are absolutely gutless in the power category. Top out at 12-14 mph and when the grass meets the blade can't cut more than 1.5-2 mph without killing the engine. How many of those 12 mph Z turn will actually mow at 12 mph, or is mowing speed a little closer to 4 mph The early 70's cub cadet 106-107 126-127 or JD 110-112 with a 10 or 12 hp engine and 42 in deck would out cut some of the high hp Z turn on the market today.

I have never owned a Z turn but have owned several GT over the years. Owned a 15.5 hp 42 inch tractor with a 6 speed and a 25 hp 54 inch tractor with the 6 speed and guess which tractor I could mow the yard faster with? The 42 inch 15.5 hp tractor by a half hour. I have repaired hundreds of Z turns over the last 20 some years and the number of those that I would consider owning 2. One was a Grasshopper front deck and the other was a Gravely


#14

PTmowerMech

PTmowerMech

gregjo1948 said:
Is it an opposed twin or a V twin?
Click to expand...

Opposed twin


#15

PTmowerMech

PTmowerMech

gregjo1948 said:
If you put 10hp on a full grown Ferris Z, it would have trouble turning the blades without mowing grass. These machines spin their blades extremely fast, travel over 10mph while mowing uphill, and weigh upwards of 3/4 of a ton. 10hp will work OK on a YT/GT with a 42" deck weighing 300lbs. mowing at 4mph but it'll take all day to mow a lawn that a 61" Ferris will do in 2 hours. Until you operate a Ferris with the totally independent suspension and mow, what used to be hay fields/pastures, you can't imagine how much better it rides than a YT/GT. YT/GT machines are good enough for a small city lawn and are handy to pull around a little yard cart but if you want to get large or many lawns mowed, a Z with bigger hp is the way to go. 10 hp engines won't work worth a hoot and won't last on a Z. That's why the manufacturers install the big hp twins, triples, and even diesel engines. Sorry about my rant but, 10 hp on a Z just struck me wrong!!!!
Click to expand...

Yeah those big ferris machines are like tanks. They're the Cadillac's of mowers. I can see how even a 18ish hp would have trouble holding up especially with some say 9 or 10" grass. But on a normal lawn, with few inclines, I think they'd do ok. If the engine was in descent shape.

Last year, my main gig was buying used, fixing and selling. I had a lot of folks trying to get $100 or more out of an L head 10 to 15hp engine on an older mower (that needed work). And I'd ask them why they were selling it. And the typical answer was they were going to get them a new one with at least a 20hp engine on it. In which I respond with, "everyone wants the high hp engines. And how hard it is to even sell an old mower, and make any profit out of it. Especially when I gotta put $100+ in it just in parts and labor.


#16

B

bertsmobile1

ILENGINE said:
The point I was trying to make was back about 30 years ago the garden tractors with 42-48 in decks were 10-16 hp gear or hydrostat. Even the Case 446 which was made by ingersoll was all hydraulic drive, and had a 4 foot tiller or rough cut mower available that were hydraulic drive like a skid steer attachment, And they were 16 hp, then sometimes around the early 2000's is when the HP took off and everything got bigger about the same time that EPA tier 1 came into play. I was working on 7.5 hp push mower engines fitted on 22 inch push mower that were just 5 years prior were 3.75 hp engines.

Some of the Z turns with 25-27 hp engines I have worked on the last few years are absolutely gutless in the power category. Top out at 12-14 mph and when the grass meets the blade can't cut more than 1.5-2 mph without killing the engine. How many of those 12 mph Z turn will actually mow at 12 mph, or is mowing speed a little closer to 4 mph The early 70's cub cadet 106-107 126-127 or JD 110-112 with a 10 or 12 hp engine and 42 in deck would out cut some of the high hp Z turn on the market today.

I have never owned a Z turn but have owned several GT over the years. Owned a 15.5 hp 42 inch tractor with a 6 speed and a 25 hp 54 inch tractor with the 6 speed and guess which tractor I could mow the yard faster with? The 42 inch 15.5 hp tractor by a half hour. I have repaired hundreds of Z turns over the last 20 some years and the number of those that I would consider owning 2. One was a Grasshopper front deck and the other was a Gravely
Click to expand...

And I thought it was just me.
Yep the 8/32 gear & chain drive Rover makes an lot of 20Hp mowers look stupid.
It will out mow just about any residential made now days in both speed & quality of cut.
It will also run through 5' tall pasture that chokes all but the top end commercials .
Just like cars, the easiest way to make them look better is a bigger engine.
Abd despite being a side banger it will run 2 hours on a gallon of fuel.


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