The needle valve operated by the float is stuck open...but this leaks into the engine when the mower is not running...how it is getting in the engine while running is someone else's question to answer.I have a John Deere L-111 riding lawnmower that is getting gas in the oil. I check the oil before I start to mow and after I check it again. After mowing the oil is way past the full mark and smells like gas. I drain it out and fill with oil again and after mowing again it is full again with oil and gas. Anybody know what I might try to stop this before I end up blowing the engine up. Oh by the way I have changed the fuel pump with know luck.
Thanks in advance,
Larry
The needle valve operated by the float is stuck open...but this leaks into the engine when the mower is not running...how it is getting in the engine while running is someone else's question to answer.
If you are getting oil in the crank while the engine is sitting then the responses from the previous posts would be correct.
However as you specifically stated you checked the oil level before you started to mow and after you finished when you found it had gone up
a reasonable assumption would be that the fuel had gotten into the crankcase while the engine was running.
If it was arriving there via a stuck float needle then you would be running very rich & blowing lots of black smoke.
You did not mention this so the assumption based upon the facts presented would be the fuel was entering the crank while the engine was running but not via the carburettor.
The only other place where the crankcase & the fuel system come into close contact is the fuel pump.
If it has a mechanical fuel pump then look at the seal and diaphragm
If it has an impulse pump then replace it as the diaphragm will have a hole in it and will be pumping fuel into the crankcase every time the piston goes up.
You can confirm this by checking the impulse line for fuel and double the confirmation by sucking on the impulse port on the pump.
It should suck in a little as the diaphragm moves in then hold vacuum for better than 2 minutes.