Local Confusion

I am confused about the conditions for valve clearance setting in my motorcycle. Some say that it has to be set when the engine is cold while my local mechanic insists that the engine needs to be hot. What is the correct procedure?

Dipankar Ghosh, via social media

Dear Dipankar,

All tolerance settings must be performed on a cold engine because when the engine is hot, the metal components are subject to expansion. So, any setting done at that time will not be consistent with the correct clearances needed for optimal functioning. Therefore, checking or setting valve clearance for a hot engine is incorrect and rather unsafe too.