My mower will not start. I removed the spark plug and it was gunked over with oil. I replace with new spark plug and still wouldn't start. When I removed new spark plug it was also covered in oil. My guess is the oil is affecting the spark plug, but what is the cause of the oil. Is there a crack in my engine that is causing the leak?
#2
EngineMan
Could be the head gasket, but its more likely to be piston ring(s)
You don't say what make or model it is, so can't give you more info. the more info you give us, the more help we can give you.
Check the engine oil. Is it overfull? Does the oil smell like gas? Sounds like the carb has ran gas into the engine and mixed with the oil to me. Or you tipped it over and oil ran into the cylinder.
This is happening to me too. Someone in my neighborhood tossed out what appeared to be a perfectly good looking Toro lawn mower (Model #20017, Serial #250058039). Once I got it home I pulled the spark plug only to find it swimming in blackish oil. The little gas it had did not seem too old and the oil doesn't seem to be that bad looking either. I thought I would start with a general tune-up (new spark plug, air filter, oil change) but also change the head gasket. Once I removed the head cover, I noticed a lot of oil inside but also a dark film all around the inside on both sides. I'm assuming there shouldn't be any oil in this area. My question is, would changing the head gasket solve the problem with oil getting on the spark plug? Or am I looking at a bigger problem?
This is what I would do -- takes about 10 minutes
a) Check oil level-- usually when people overfill the engine just stops once it gets warm enough remove enough oil to get to the midpoint of stick.
b) only tip towards the bottom end of the crank -- if oil gets into the carb, you're into clean up mode. pull the filter and see if there is any visible oil.
c) you've pulled the spark plug, put a piece of cloth over the end of the spark plug hole and so give the engine a few pulls and see if anything sprays out
d) clean the spark plug with carb clean and regap if necessary and reinstall
e) spray the carb with carb clean.
If it smokes like crazy but runs, you've cured the problem. Run it until the smoke stops and hope that no one calls the fire department.
Anything else needs a compression test and a competent repair tech.
