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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 28668
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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At high rpm the engine loses power and smoke (blue) billows

Customer Question

at high rpm the engine loses power and smoke (blue) billows from the exhaust.,It happens especially under load. What is the cause/fix
JA: Can you guesstimate how old the engine is? And has it done anything like this in the past?
Customer: The tractor was purchased new in 2009 although it is a 2008 model Cub Cadet 2542 with a mod CH20s. It has done this on occasion before but it seems worse now. Usually it runs fine no noise no knocking nothing.
JA: Do you plan on doing the work yourself?
Customer: If I think I can
JA: Anything else we should know to help you best?
Customer: I checked the oil this last time and the stick had a reading all the way up to "from" and it only had 2 qts of oil......
Submitted: 10 months ago.
Category: Small Engine
Expert:  Curtis B. replied 10 months ago.

Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!

Expert:  Curtis B. replied 10 months ago.

Twin Kohler, CH20.. So does the oil have gas in it? Thinned oil , from gas in the oil, will cause the smoke. I would try changing oil and filter, then test, If it is getting fuel in the oil. then the carburetor or fule pump is leaking gas into the oil.

Customer: replied 10 months ago.
The oil seemed to be really thin, possibly gasoline in it. I have changed it andthe engine has not had the problem so far. The oil had about 30 hours on it.
Customer: replied 10 months ago.
I do not wish to talk to anyone at this time
Expert:  Curtis B. replied 10 months ago.

OK> What does it have for a fuel pump? I see no fuel pump. Gravity feed from the tank? May have a needle valve and float leaking in carb.

Customer: replied 10 months ago.
Am I going to get any further response? I have no idea. I can tell you that the fuel tank is in the rear of the tractor and that engine is not fuel injected
Expert:  Curtis B. replied 10 months ago.

Yes, it shows the tank and the carburetor, but does not show a fuel pump. So fuel can leak into the vent to crankcase through a leaking needle valve.

Customer: replied 10 months ago.
If it is a carburetor problem, i'll have a mechanic rebuild it if necessary
Expert:  Curtis B. replied 10 months ago.

OK> Thanks, ***** ***** to close if satisfied.