JD Z960M w/Kawi 31HP Losing Power

[jac233]

Hello,

I can't figure this out!!

My zero turn with 31HP Kawasaki runs fine for a while. In fact, I cut grass for about an hour today with no problem.

Then, it starts sputtering, backfiring, and finally just loses power and eventually just stalls out.

Seems to come back to life for a little while after I let it sit then repeats the issue.

I changed spark plugs, checked carb and it looked clean but gave it a shine up anyway.

Thoughts?

 

[Bertrrr]

You probably have a fuel delivery issue- fuel pump or suction lines leaking air or collapsing internally, Being it starts up again when it's acting up , it does not sound like an ignition issue

 

[bertsmobile1]

And to add to Bert above
Debris in the fuel tank plugging the outlet and/ or blocked fuel tank vent
When it stops pull the fuel line off at the pump
If it sucks back you have a vent problem ( confirm by mowing with the cap loose )
If not them blow back up the fuel line
If that is very hard to do and you can start up right away that equals a blocked outlet or collapsing fuel line
New fuel line is 3 or 4 tubes inside each other and the inner lining is very thin & very fragile

 

[jac233]

Thx, but why does it work for a while before the issue occurs?

 

[StarTech]

Because if it is trash in the fuel tank it get sucked up in the fuel pick tube and then stop at the reduced 90 degree line adapter. Then you shut down the engine fuel back flows and washes the trash back out. Then it just cycles this way until the tank is cleaned.

I had one JD here that actually had a Yellow Jacket wasp and a honey bee that was the culprit here.

 

[jac233]

Because if it is trash in the fuel tank it get sucked up in the fuel pick tube and then stop at the reduced 90 degree line adapter. Then you shut down the engine fuel back flows and washes the trash back out. Then it just cycles this way until the tank is cleaned.

I had one JD here that actually had a Yellow Jacket wasp and a honey bee that was the culprit here.

Ahh...got it. Ok, thanks for explanation. I will check this and see if I can find a culprit.

Would you rule out the coils?

 

[jac233]

I pulled the fuel lines apart and didn't see any blockages. Fuel is getting to the filter but I changed it anyway.

It seemed to run fine for about 25 mins so not sure if the filter did the trick or if it's just a matter of time until it happens again.

Going to try and empty the fuel tank and see if I can find any trash in there.

 

[bertsmobile1]

FWIW I had a similar problem a while back ending up doing 3 warranty returns on it
Ended up being the section of the fuel line that connects to the fuel pick up had delaminated
So when running fuel ended up getting between the 3 layers of rubber in the tube which cause the walls to swell & block off the fuel flow
First time I have had this happen but I now try some Tygon single wall tube for diagnosis

 

[jac233]

Thx, it's running fine now, so I'm wondering if it was just the fuel filter that was clogged. I didn't think that was the issue b/c there was fuel in the line post filter and plenty in the carb.

I guess I will find out when I keep running it if there is something in the tank that comes back to haunt me!