Why would you have gas in your oil?

bad fuel pump

AnswerIf the engine is running from a fuel pump that is NOT mechanically connected to the block, there is really only one way that fuel can get into the oil. It's usually from a condition called "wash down", where too much fuel is delivered to the cylinder and it leaks past the rings. The engine has, no doubt, been running quite poorly, and if you would have noticed, there was plenty of black smoke out the exhaust. You probably have one or more stuck injectors that leak fuel and floods the engine constantly. That condition needs to be fixed as soon as possible, since wash-down removes oil from the cylinder walls and the rings end up rubbing against bare metal. It also thins the oil and causes problems for the bearings.

On the other hand, if you DO have a mechanical fuel pump (no doubt it's an older vehicle with a carburater) it could just be a worn out fuel pump diaphragm that allows fuel to leak into the crankcase. But that's rare since those type of fuel pumps usually had a weep hole that caused a lot of fuel stink when they leaked.

I only retailed for 38 years in the lawn & garden parts business and repair.....if a machine is transported....on a trailer or truck, even the trunk of a car....this causes the needle in the carb to bounce...that is where alot of damage can come from....When transporting, its just a risk, some say run them dry and turn off the fuel and run it out....well if you do that it will drop the float level and then you do have more of a chance of damage.