Mower runs great and cuts fine for about 10 minutes but then starts running very rough with or without deck engaged. It will continue to return to normal without any load... cutting deck or moving. I have replaced fuel filter, fuel line, fuel, spark plug, pulled flywheel and shear pin was perfect... Any ideas??

Joe

Seems like electronic component breaking down once it gets hot?

This might be an issue, and might not be. Do you use Premium gas?
I have 2 riding mowers, 2 weedeaters, a chainsaw, and leaf blower, and mow for others.
Four years ago, I stopped using Regular gas, on the advice of my Small Engine repairman!
I haven't had a carburator problem since using Premium... costs a few cents more, but is well worth it. Good luck. Regular gas has many, many more impurites in it than just 10 years ago.

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Originally Posted by fredg

This might be an issue, and might not be. Do you use Premium gas??
I have 2 riding mowers, 2 weedeaters, a chainsaw, and leaf blower, and mow for others.
Four years ago, I stopped using Regular gas, on the advice of my Small Engine repairman!!
I haven't had a carburator problem since using Premium....costs a few cents more, but is well worth it. Good luck. Regular gas has many, many more impurites in it than just 10 years ago.

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No, unfortunately one can for all of my engines... 87% with Ethanol... haven't had problems before. Should I add a "boost"?

Will always use Premium without Ethanol going forward!

Drained tank and refueled but still same issue... any other ideas on the electrical side?

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Originally Posted by Joe1317

Will always use Premium without Ethanol going forward!!

Drained tank and refueled but still same issue... any other ideas on the electrical side??

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Still looking for answers... anyone?

High octane is worse on the engine,any good small engine mechanic should know this,
.check your gas cap make sure its venting.

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Originally Posted by DG

high octane is worse on the engine,any good small engine mechanic should know this,
.check your gas cap make sure its venting.

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Now THAT would be a simple fix! I'll definitely try that tomorrow

Tried the gas cap... not that. Looked into the carb next... I removed the air cleaner and found that I had some oil blowing back through the head into the carb causing it to run rough (even though only apparent under load".

So why do I have oil blowing back from the engine?

Quote:

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Originally Posted by DG

high octane is worse on the engine,any good small engine mechanic should know this,
.check your gas cap make sure its venting.

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Tried the gas cap... not that. Looked into the carb next... I removed the air cleaner and found that I had some oil blowing back through the head into the carb causing it to run rough (even though only apparent under load".

So why do I have oil blowing back from the engine?

Check engine oil ,and make sure it doesn't have gas in crank case ,or over full.
Could be needle and seat in carb.

Quote:

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Originally Posted by DG

check engine oil ,and make sure it doesn't have gas in crank case ,or over full.
could be needle and seat in carb.

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Okay... gas in the oil... what causes that? Noticed the oil vary very thin...

Need to clean the carb , maybe replace needle and seat.
Gas is running through the carb into crankcase.