car engine

[duan]

Why is there oil in the carburetor

[dodgyshirt]

To act as an hydraulic damper in an SU carb.

[Mortartube]

If there is an excess of oil, it is possible that the crankcase breather pipe is blocked and pressure builds in the sump, forcing oil back up through the carb and into the air filter. Fairly common on some VW's, golf, polo etc

[Clanad]

In the US, on much older cars there was actually oil in the shroud above the carburetor that served as the air filter. One had to change it quite often. The last one to use that device was probably in the 1950's however.

[Maxrom]

I agree with Mortartube, I once had an old and very tired Mk1 Fiesta and that had the same problem. The air filter housing would regularly have excessive amounts of oil build up in it. This was down to a dodgy breather pipe also.