oil on top of cylinder head

[Jurney]

Have a flying horse 66cc engine and have oil on top of head could it be a bad head gasket it seems to be coming out of the mounting bolts. head bolts are tight. Spark plug is tight, also I don't have as much top end as I used to. on a flat road was able to go about 30mph all out now only able to go about 18mph. the engine has about 400 miles on it or less.

A second thought I had was could muffler pipe have a build up of oil in it. I bent my own exhaust it comes out of engine down and under bike then back up to the height of the center of rear tire.

A third thought I have is, could it be frothing in carb, because it seems that the engine dropped a little and the air cleaner is touching the bike frame just slightly.

The head gasket to me seems the like most likely due to oil but wanted to hear your thoughts

Thanks
Jurney

 

[Greg58]

Since the oil is on the head I’d start there, pull the head and check it for flatness. Tape 400 grit sandpaper to a true flat surface and sand the head in a circular motion like waxing a car. If it’s out you will notice, once it’s true reinstall it. A new gasket is best but you can reuse the old one, torque the head bolts to about 12foot pounds, don’t over tighten.

 

[Jurney]

Thanks I will take a look.