Hey guys-

My riding lawn mower is getting gas in the oil somehow???

Anyone know how this might go about happening?

Someone opened the oil cap and put in some gas...

..thats about the only way it can happen.

There is no other connection between gasoline and oil circuits that I can think of.

Other than a freaky failure of two sets of pipes.

It could be a couple of things, but I would suspect the carb first. Is the engine hard to start? Have you experienced flooding? Do the plugs show any signs?

Lastly, as Vintage mentioned, any chance someone in the family decided to refuel and picked the wrong hole?

Tram,,this is a easy one..if you are lettting that goat in your avaitar change your oil..he evidently cant tell when hes putting oil in the gas/oil compartment..please take off his pvc pipe...so he can see again..

WAG-
If it has a mechanical engine-driven fuel pump, then a leak there could let fuel enter the crankcase.
My brothers 69 Chevelle ( he had it in the early 80s) did exactly the opposite. A bad diaphragm was letting oil get into the fuel.
Tons of blue smoke. Probably gas was going the other way as well, but it burned about a quart of oil every other day, so there would be no time for it to accumulate.
Pat Mackenzie

this sounds like something Jiffy Lube would do..lol...boy ive heard some horror stories about those guys..

Originally Posted by pmackenzie

WAG-
If it has a mechanical engine-driven fuel pump, then a leak there could let fuel enter the crankcase.
My brothers 69 Chevelle ( he had it in the early 80s) did exactly the opposite. A bad diaphragm was letting oil get into the fuel.
Tons of blue smoke. Probably gas was going the other way as well, but it burned about a quart of oil every other day, so there would be no time for it to accumulate.
Pat Mackenzie

Not sure about that - don't think MY ride on mower HAS a fuel pump..all gravity feed.

Tons of blue smoke and oil in the combustion chambers is more likley to be worn or broken rings, especially in engines that feed the oil breather back into the inlet manifold.

7 post in a thread with the words gas and oil in it and know one has blamed bush yet......we have a record.....

If the fuel tank is higher than the engine, check the needle & seat in the carb. It could be flooding the carb, letting the fuel drain down the manifold, past the intake valve and then seeping around the piston rings into the crank case.


on edit:

Blame Bush.

Blame Bush

Ha....

Head gasket?

Most likely , it is excessive blow by passed the piston rings. How many hours do you suppose is on that engine?

alan scott:If the fuel tank is higher than the engine, check the needle & seat in the carb.
It could be flooding the carb, letting the fuel drain down the manifold, past the intake valve and
then seeping around the piston rings into the crank case.

Thats a possibility. Only, I would suspect that the engine would be very difficult to keep running
with any type of reliability.Tram did not mention how or if the thing runs. Also. This can only be true if its an overhead valve engine, or maybe a horzontial lying down on its side engine.

What model of lawn Tractor is it. what year is it.

Originally Posted by alan_scott

If the fuel tank is higher than the engine, check the needle & seat in the carb. It could be flooding the carb, letting the fuel drain down the manifold, past the intake valve and then seeping around the piston rings into the crank case.


on edit:

Blame Bush.

This is most likely if your engine is gravity feed for the fuel.. If the fuel is delivered via a mechanical fuel pump where the pump is attached to the engine, it is likely that the pump diaphram is leaking gasoline which runs out of the pump and down to the oil sump.

electroman7 :This is most likely if your engine is gravity feed for the fuel.. If the fuel is delivered via a mechanical fuel pump where the pump is attached to the engine, it is likely that the pump diaphram is leaking gasoline which runs out of the pump and down to the oil sump.

I don't know. Most mechanical fuel pumps have the diaphram well below the opening where the rocker lever extends into the block. I know this picture is of a typical automotive pump, but you can see what I mean. I am assuming Trams lawn tractor is a little one with probably a briggs & straton on board. Its not going to have a pump like this one. It will most likely has a pump attached to the carb.