yahama big bear 300 gas mixing with engine oil

[duckhunterdave30]

I have a yahama big bear 300 and gas is mixing with the engine oil. What could be the causes of this? It does not smoke and it still runs good.

[mywifeknowseverythin]

If the fuel is gravity feed, the carb may appear to have a good needle and seat, yet it may not be closing fully. It's also possible the needle and or seat are damage or blocked do to debris in the carbs fuel bowl.

Also,,,,Be sure to turn you fuel off every time you shut your bike down......Also check your Float....

[DirtDemon]

Likely worn valve guides or rings allowing compressed air/fuel to leak into oil system.

[SunLrider]

If the fuel is gravity feed, the carb may appear to have a good needle and seat, yet it may not be closing fully. It's also possible the needle and or seat are damage or blocked do to debris in the carbs fuel bowl.

Also,,,,Be sure to turn you fuel off every time you shut your bike down......Also check your Float....

i would go with the carb not closing fully

[downfour47304]

could also be a head gasket

[mywifeknowseverythin]

could also be a head gasket

Maybe I havent had enough coffee yet.....But could you Eplain to me why you think its a Blown Head Gasket????

Dave...Have you found the problem yet????

[DirtDemon]

If the head gasket leaks between the combustion chamber into the timing chain slot you could get gas in the oil.

[duckhunterdave30]

Found the two problems. gas valve was not working right letting gas by. then the needle was not setting to keep it from going through carb and it to piston. just sitting there with that pressure was letting it pass by rings. it is all fixed now and running good.

[mywifeknowseverythin]

If the fuel is gravity feed, the carb may appear to have a good needle and seat, yet it may not be closing fully. It's also possible the needle and or seat are damage or blocked do to debris in the carbs fuel bowl.

Also,,,,Be sure to turn you fuel off every time you shut your bike down......Also check your Float....

Glad I could help:laugh: