Gas in the oil???

Greenfrog · Mar 23, 2022

Is there something about not shutting off the gas in long time storage, over the winter, and the gas seeps through the carb, then into the oil? Especially if the float is stuck, .or something like that? Thx n advance on explaining this.

TomIn · Mar 23, 2022

Gas will seep into the oil fairly quickly if:

1. The float needle valve does not seal. (Sticks open to some degree or is damaged so that it will not seal.)
2. The gas tank is higher than the carburetor. (Gas will not normally flow uphill.)

T.R.K. · Mar 23, 2022

I just want to add it happens much more often when the gas has alcohol in it. Alcohol likes water and a drop of water in the needle valve allows it to seep gas.

Bigeasy16 · Mar 23, 2022

With our equipment if we didnt shut off the gas itd leak in the oil in less than a day. Long as the gas got shut off it was fine though. Tomins got it.

560Dennis · Mar 24, 2022

Tight system will create a vacuum when it cools down in winter pulling fuel into oil in the crankcase ,had the problem on Datsun truck
Watch a fuel can expand and contract

Mule Meat · Mar 25, 2022

All it takes for fuel to get into the oil is a stuck float valve and an open
or not seated intake valve. Or a bad vacuum type fuel pump.

Gas will flow past the piston rings into the oil. Past worn valve guides into the valve cover/s then through the oil return.

Vacuum type fuel pumps. The vacuum diaphragm that pulses when the engines cranks can crack allowing fuel to seep into the crankcase.

Fuel type nor grade has nothing to do with fuel entering the oil pan.

Gas in the oil???

Greenfrog

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TomIn

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T.R.K.

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Bigeasy16

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560Dennis

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Mule Meat

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