I checked the oil in my Onan B48M (in my '78 Sears GT18) and it looked a little runny. I tried to give it the snuff test to see if I smelled gas, but my sniffer sometimes just smells oily greasy stuff and can't tell the difference. Is there some other test I can do to see if my carb flat has let gas flow into the block?
How to tell if gas is in oil?
Posted October 27, 2015 - 08:16 PM
- Lauber1 said thank you
Posted October 27, 2015 - 08:23 PM
If the oil is over full, thin and as you said, smells like gas. You can do the flash test with a small amount in a bottle cap, hold a lit match beside the lid, if there's gasoline in it the fumes will ignite on the surface beside the lid.
Edited by toppop52, October 28, 2015 - 06:19 AM.
- DougT, Alc, Lauber1 and 2 others have said thanks
Posted October 27, 2015 - 09:40 PM
When in doubt change the oil. It is cheap insurance. Good Luck, Rick
- Lauber1, HDWildBill and Marty'70 have said thanks
Posted October 27, 2015 - 09:48 PM
most of the time I find if you watch the oil level, it the best indication of extra fluids in the wrong place. A lot of time this problem can be solved by installing a cheap shut off valve in the fuel line.
- boyscout862 and propane1 have said thanks
Posted October 28, 2015 - 06:19 AM
Yep, I was hung up on determining if there was oil in the gas, but as stated, if in doubt change the oil and always use a shut off valve. Gravity and vacuum are easy to come by and cause a lot of trouble.
- boyscout862 said thank you
Posted November 16, 2015 - 06:30 PM
I wasw in the small engine field for 30 years, I would just remove the dipstick and hold a lighter to the end of it where the oil is, if it burns by itself, it has gas in it, if it doesn`t, it`s usually OK. As for just changing the oil to be safe, you will still get gas in the oil if you don`t fix the problem. A lot of times it`s a leaking fuel pump diaphragm or flooding carb that`s feeding gas back through the breather tube back into the crankcase.