QuestionWe bought a used, but good (we hope) Snapper riding lawn mower (30 inch 1997 B&S 9hp) recently. We thought the float was stuck open, because after it would run a while and was turned off gas seemed to come out of the carb. Yesterday evening I took the carb apart and cleaned it well, but the float and needle were ok. When I started it this morning-- with the air filter off-- it ran well at low speed, but when I reved it up, it appeared that a mixture of gas with some oil gushed up out of the carb. Actually, it came through a rubber tube from a rectangular cover on the side of the engine.
Wow, I have no idea what this could be. A stuck valve? My friend thinks it is just stuff in the intake manifold from when he turned it upside down, or too much oil. But this has happened several times, and the oil level is just a bit low. Please help if you can. I am still researching also.
AnswerHi Richard,
A leaking intake valve would cause back pressure through the carb. A compression test would check the valve.
As far as what is coming through the carb, oil might have gotten where it shouldn't, from tipping or being overfull at one time. Fuel would leak into the carb by a leaking float needle and seat. You will need to check things out.
Let me know what you find.
Michael
