[christopher1978]

I have a craftsmen 12hp mower. I have gas in my oil, the mower will not crank. I don't know how the gas is getting into the oil. What should I do?

[Stratmando]

Carb Float, Sticking Injector? If OK,
Check Compression.

[christopher1978]

Carb Float, Sticking Injector? If OK,
Check Compression.

Thank you I will check that out! Also would that also cause gas and oil mixture too shoot out of muffler in the front? I think that is the muffler

[Stratmando]

I had a Kawasaki Mach III, had fuel go out the exhaust. Pulled the Carb apart and had Main jet sitting in the float bowl.

[21boat]

If crankcase oil is getting contaminated with gas, that is if the Head Gasket is good. That can be check with a compression check to see if the valves and rings are good.

It could be the carburetor needle valve or float and its letting gas leak into the carburetor and flooding the cylinder(s) when the Engine is sitting in time.

The Gas will seep by the rings and get into the crankcase. The oil is to high and thinned and gets by the rings and into the cylinder when you run the engine. We call this "blow By" This is what usually causes white smoke.

[Pinion]

It's going to be a carburetor issue. Float sticking and/or the fuel shutoff solenoid (if it has one). Very common issue after they've sat for any amount of time.

Check the carb float to make sure that it doesn't have any cracks or holes. Clean the carb with some carb cleaner. While you still have the bowl off the carb put some gas in the tank and physically hold the float up and make sure it's not seeping gas. If it's not then you should be good to go.
Make sure to drain all the oil and gas out of the block. Let it sit and drip for awhile. Fill with fresh oil and mow grass.