Helping a friend with his bike and depressions have formed where the head gasket combustion rings contact the head.
I have not come across this on my CB750 bike rebuilds and would appreciate views and experience.
Is it OK to lightly skim head and what is limit?
Has anyone experienced this before and likely cause?
The combustion rings on new gasket will help seal the extra gap caused by grooves, but what is the limit?
Views and thoughts appreciated.
