Topic: Need advice on valve condition. 1978 cb750F

[eosmontana]

I'm working on redoing the top end of my cb750f3 and needed some advice. I've got the engine apart and the exhaust valves had a lot of play in them so it looks like I'll be needing new valve guides for sure...It also looks like the valves may be done for as well. Any experts out there wanna tell me if these are worth re-using or if i would be better off getting some new ones?...and any other budget minded things i should redo besides rings, honing, gaskets, and cam chain tensioner. Thanks!

[Rigid]

Check out the end of the stem, this is often the death of a valve due to damage.  The sealing surfaces on the face of your valves don't look excessively worn.  They could be ground very lightly or lapped to check their seal.  A dimensional measurement of the stem outside diameter is in order.  The wear is often in the softer guides but the stem can be undersized also.  Many will suggest just buying everything new.  I don't agree.  Parts that pass inspection and reconditioning are good parts.  I base my opinion on 30+ years as an aircraft and motorcycle mechanic specializing in air cooled piston engines.

[eosmontana]

Thanks for the insight Rigid...  Anyone know what the measurement of the outside diameter of the stem is supposed to be?

[Rigid]

Should be in the manual available on this site.  That is what I used on my last head job.  Rock on.

[liPPy]