Hi. My Ryobi mower (Kohler Courage 19 hp) runs really rough and sputters/backfires hard under load. First season doing this. Cleaned the carb 2x, new air filter, plug, and the gas is new. Fuel solenoid seems fine. Fuel supply seems fine. What's weird is I thought I had the problem fixed (after the 2nd carb cleaning) but during mowing, after about 30 minutes of use, I turned a corner under normal mowing conditions and the problem immediately returned as if a switch had been thrown. Now the engine also runs rough/sputters/surges under all throttle settings. I get a little oil in the exhaust at startup (been that way for a couple seasons). Other than that, the mower has runs fine for 5+ years. Any help would be appreciated. Thanks for your time.
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Engine runs rough and backfires under throttle
- Thread starter bugbug98
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Export threadbertsmobile1
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Remove the fuel tank & clean it out.
Most likely crud in the tank blocking off the fuel line.
Most likely crud in the tank blocking off the fuel line.
Ok I will give that a try - thanks. I do recall the fuel filter looked full of gas, and when I cleaned the carb, the leakage of gas from the line when I removed it was appreciable, so I am guessing the fuel supply is fine. Nevertheless I will do as you suggest. Thanks for your time in replying.
Could also be valve clearances changing the timing a hair. Or did you hit something shearing the fly wheel taper key, also moving the timing. My Intek protests when its valve lash is off.
bertsmobile1
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A first start up problem is generally corrosion, fuel deposits, dirt , rodents or insects.
You seem to have the first 3 covered so whip the top cover off and check the line to the coil had not become a mousy teething ring and a bit harder the exhaust has not become bug Hilton.
The last and least common is a sticking valve
You seem to have the first 3 covered so whip the top cover off and check the line to the coil had not become a mousy teething ring and a bit harder the exhaust has not become bug Hilton.
The last and least common is a sticking valve
Ok - update - the fuel supply is fine. No blockages. The wires are all intact - no damage from mice. Exhaust is free flowing. Ran fine for 10 min tonight and was mowing, and then an imaginary switch went off and it started sputtering and jerking. Took the fuel solenoid stopper off (to take it out of the mix) and that didn't change anything. Still running horribly. Not sure what else to do. Thanks for everyone's help.
Just a thought but is the spark weakening when this happens?
Hmm. Not sure. I don't get that impression. How would I check?