burnt valve

[broook]

This is what I found when I removed the head last fall. Looks like a beaver chewed on it.

[bobber]

Valve clearance too tight or non-existent allowing hot exhaust gas to "chew on it like a beaver". When I rebuilt my '82 X I brought the head to a dealership in Edmonton and told them to go at it. I think 11 seats were replaced along with some guides and a whack of valves. For the amount of tooling required to measure, press, grind valves the head is the 1 component of an engine I would recommend having a dealer do. My '80 X was same story but didn't get quite as large a bag of parts back or as big a bill!!!!!

[broook]

Valve clearance too tight or non-existent allowing hot exhaust gas to "chew on it like a beaver". !!!!

That was my first thought. Just checked on my past maintenance records and that valve stayed at a constant .004 thou. from 1990 when I bought the bike up until last year. But i did notice that on that particular cylinder it had lower compression so it could have been leaking for a while.

Oh well. Two new exhaust valves are now in place compliments of one of our great ICOA members. Thank you.

[pbransonii]

It wasn't in number five was it?

[broook]

It wasn't in number five was it?

It was the 5th exhaust valve over. #1 ex in #3 cylinder.