as above,
If you are asking about oil drip or mist coming out the impulse breather hose at the air filter.
but
if crankcase has too high a level of oil and or oil contaminated with gas and the crankcase oil level is too high.
On some small engines you will see little bit of oil at the air filter breather when full up and when the engine oil level drops just little bit like1/8 to 1/4 inch on the dip stick all will be ok. The engine kinda wants to seek it''s own oil level little bit below full on the dip stick or oil level hole. It's just the nature of the beast.