Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage

indiggio

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
So I get the mower out this year and have been having all sorts of issues with it.

Charged up battery and installed, put in fresh gasoline.
Fired up fine and pulled it out of shed and set it to medium speed to shut doors on shed.
Engine starts surging and then dies, never done this before.

Fire up again and give it full throttle and seems to be running ok.
Pull blade engage and engine bogs way down and stalls.
Start it back up and head to driveway to look it over.

Add some SeaFoam to gas tank to hopefully help clean out anything in carb.
Start it up and full throttle, engine sounds good, but starts this periodic, like every 10 seconds pretty regularly, dropping power.
Try driving some laps around driveway and it still doing this. Power drops not to the point of stalling, but noticeably lower than full throttle.
What would cause such a regular, periodic drop in RPMs?

I've got a clear gas filter and notice that there's only a trickle of gas in the filter, yet the engine runs just fine.
Is this normal?
Note that I also replaced the gas filter last year along with oil change.

Pulled out air cleaner and blew off filter, wasn't too dirty.
Pulled off air hose to carb and looked in, noticed it was kinda "wet" by choke butterfly, should it be like that or should it be dry in there?

Pulled on blade belt and am able to move blades, but hear grinding from (I think) the PTO clutch? Should it grind like that?
I took a .015 feeler gauge and slipped it in check holes and distance seems to be ok, just a bit of resistance.

Fired it up again and this time it ran without any surging at full throttle.
Tried engaging blades and it bogged down and stalled.
Started up again, full throttle, engaged blades and same thing, bogged down and stalled.
Third times the charm?
Fired up again, full throttle, engage blade and VROOOM, blades spin up just like normal.
Held my breath and did the lawn and mower worked fine.

Scared what next week might hold!

Not sure what to check?
When it works, it works great.

What would cause this intermittent periodic surging?
What would cause it to sometimes die when engaging blades but other times fire them up as usual?

Thanks!
 

plateauman57

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
Does it have two coils? I'm thinking a few years ago mine would die when I engaged the blades and it had a bad coil. I'm not even a shade tree mechanic so I may not know what I'm talking about. I took it to the dealer for them to diagnose and repair. Don't have it now, upgraded to a turf tiger. Good luck.
 

indiggio

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
Does it have two coils? I'm thinking a few years ago mine would die when I engaged the blades and it had a bad coil. I'm not even a shade tree mechanic so I may not know what I'm talking about. I took it to the dealer for them to diagnose and repair. Don't have it now, upgraded to a turf tiger. Good luck.

Mmm... Don't know if it has 2 coils or not. To tell you the truth, I'd have to do some research into what/where the coils are and how to test them.

I guess I could consider myself a shade tree mechanic, but if/when it goes beyond basic stuff, I unfortunately have to turn it over to the real ones.

Thanks for the suggestion though.
 

bertsmobile1

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
:welcome:

Surging is nearly always crud in the carb, blocking off the fuel passages so spraying carb cleaner will do nothing.
You can get a bit of corrosion in the jets over the off season which may or may not break free and either block the carb or pass right through the engine.
Water condensing in the bottom of the carb can also cause similar symptoms.
Not enough to kill the engine outright but just enough to cause rough running.
Then there are problems getting the fuel to the carb, blocked fuel outlets in the tank, fuel lines, fuel filters etc etc.
To run, the engine only needs to supply fuel faster than the main jet can pass it into the engine .

If it is just seasonal degregatin then oft it will clear up and pass right through the engine , if it persists the remove the carb and clean it out thoroughly.
 

indiggio

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
:welcome:

Surging is nearly always crud in the carb, blocking off the fuel passages so spraying carb cleaner will do nothing.
You can get a bit of corrosion in the jets over the off season which may or may not break free and either block the carb or pass right through the engine.
Water condensing in the bottom of the carb can also cause similar symptoms.
Not enough to kill the engine outright but just enough to cause rough running.
Then there are problems getting the fuel to the carb, blocked fuel outlets in the tank, fuel lines, fuel filters etc etc.
To run, the engine only needs to supply fuel faster than the main jet can pass it into the engine .

If it is just seasonal degregatin then oft it will clear up and pass right through the engine , if it persists the remove the carb and clean it out thoroughly.

Yes that's what I've been reading, but what is strange to me is that at times it runs just fine for (at least) an hour.
Other times, it runs in this surging mode.

I can't help but feel like it's something going bad.
I read about coils failing or ignition module issues, but I don't know how to test those.

Thanks!
 

bertsmobile1

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
Buy an Neon tube inline spark tester and slip it on the engine.
It won't hurt the engine, just make sure it is tight on the plug & lead and that they are tied out of the way.
When it starts to play up have a quick look at the tester.
If you miss blocks of spark then you have a short or the coils are going bad.
If it sparks on even while the engine is missing then you have the fuel problem so you have knocked out 50% of what to look at.

Not uncommon for rodents to take residence in & around the engine .
They can chew through wires which then make occasional shorts or build nests that cause local overheathing.

So stop look & listen then get back with what you saw,heard & felt.
 

indiggio

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
Buy an Neon tube inline spark tester and slip it on the engine.
It won't hurt the engine, just make sure it is tight on the plug & lead and that they are tied out of the way.
When it starts to play up have a quick look at the tester.
If you miss blocks of spark then you have a short or the coils are going bad.
If it sparks on even while the engine is missing then you have the fuel problem so you have knocked out 50% of what to look at.

Not uncommon for rodents to take residence in & around the engine .
They can chew through wires which then make occasional shorts or build nests that cause local overheathing.

So stop look & listen then get back with what you saw,heard & felt.

Thanks for that suggestion!
I'll look around locally to pick up a tester.
Hopefully it will show/lead me to the source of the problem.
 

Mad Mackie

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
Your machine is probably an older model and Kawasaki has changed the engine ignition coils twice since the 90s. Kawasaki also changed the spark plug in older engines to better match the newer ignition coils. There is a "Y" electrical harness that connects to the engine ignition coils that terminates into one wire that eventually connects to the key switch. In this "Y" on the engine there are diodes installed which prevent back feed from the coils which when electrically shorted or open will cause different engine running/shut down symptoms.
The electrical clutch should be checked for internal resistance and shorting to ground. Locate and carefully disconnect the clutch electrical connector, with an ohmmeter, check the resistance between the two wires, should be between 2.5-2.9 OHMS. If less than 2.5 OHMS this means that the clutch electrical coil is shorting internally. Also check from each terminal to ground, the reading should be infinity or no resistance. In either case the clutch will need to be replaced.
I recommend that you inspect the entire electrical system one connector at a time looking for corrosion/burning on the connector male and female. This includes the key switch and the cranking relay, the panel with the key switch must be removed to do this. It can be easily lifted after the bolts/screws have been removed which will allow access to the connectors.
Another area of concern is the ground connectors that are located on one of the engine mounting bolts.
 
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indiggio

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
Your machine is probably an older model and Kawasaki has changed the engine ignition coils twice since the 90s. Kawasaki also changed the spark plug in older engines to better match the newer ignition coils. There is a "Y" electrical harness that connects to the engine ignition coils that terminates into one wire that eventually connects to the key switch. In this "Y" on the engine there are diodes installed which prevent back feed from the coils which when electrically shorted or open will cause different engine running/shut down symptoms.
The electrical clutch should be checked for internal resistance and shorting to ground. Locate and carefully disconnect the clutch electrical connector, with an ohmmeter, check the resistance between the two wires, should be between 2.5-2.9 OHMS. If less than 2.5 OHMS this means that the clutch electrical coil is shorting internally. Also check from each terminal to ground, the reading should be infinity or no resistance. In either case the clutch will need to be replaced.
I recommend that you inspect the entire electrical system one connector at a time looking for corrosion/burning on the connector male and female. This includes the key switch and the cranking relay, the panel with the key switch must be removed to do this. It can be easily lifted after the bolts/screws have been removed which will allow access to the connectors.
Another area of concern is the ground connectors that are located on one of the engine mounting bolts.

Mackie, thanks for all that great information! Very much appreciated.
It's a 2005, so I don't know if that's what you mean by an older model or not?

Could all this be due to battery? I replaced the original Scag battery that would no longer crank with a Sears Diehard 2 years ago.
Thinking back, all this seemed to start after I replaced the battery.
Should I get another original Scag battery instead?

Thanks!
 

BlazNT

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  • / Help!?! Tiger Cub/Kaw FH601V Runs Erratically, Dies on Blade Engage
Mackie, thanks for all that great information! Very much appreciated.
It's a 2005, so I don't know if that's what you mean by an older model or not?

Could all this be due to battery? I replaced the original Scag battery that would no longer crank with a Sears Diehard 2 years ago.
Thinking back, all this seemed to start after I replaced the battery.
Should I get another original Scag battery instead?

Thanks!

Neither Scag or Sears Make there own batteries.
Don't buy batteries from discount chains (son worked at battery plant Wal-Mart buyers 3rd run batteries)but other than that CCA is most important. Higher the better. Most if not all lawn mower batteries have a 90 day warranty. They are not really built very well(son worked at battery plant). Best thing to do is have the battery tested by a auto parts store. most will do it for free.
You said this happened when you changed the battery. I would look at the battery cables for clean and snug. Find where the negative cable connects to frame and remove clean and reinstall.
 
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