[footjoy]

I was at a friends house looking at a engine he bought and we pulled the heads off and there was excessive carbon like I have on my engine.

A couple days later he said the machinist told him that was caused by bad valve guides.

I guess I am curious I assumed mine was from carburetor but I never had any exhaust color or fouled plugs.

What are the causes of high carbon build up.

Thanks

Greg