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Question on a rebuild

80hondaf

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I'm in the process of rebuilding my 1980 cb750f and was wondering what I should be replacing? It has 45,000 mi. On it, the Pistons and cams look good, I will be replacing the rings and all the seals and gaskets, can the valves be ground on these? I'm the origional owner but the bike has not been run in at least five years. I'm just not sure about cam chains, cam chain tensioner etc.
 
Pretty good chunk of miles there. Tensioners for sure if bending them exposes cracking. Normal that many miles says chains too but the ones you get now are often not as good as the OEM and they break even on stock engines. You can get valve seats ground but not valves themselves, they are surface hardened and removing it at all has them go bad in under 10K miles. New valves only if something is wrong with them. Valve seals, rubbers inside primary gear housing and the clutch riveted shock plate need changing. All internal o-rings that seal oil passages.
 
The cams can look primo and be dead as a doornail from uneven wear, 750 ones don't have enough lift to really wear like the bigger ones but with that many miles?............measure them, if any lobe off by .010" or more from the spec or the others I'd be changing them. 900 cams wear worse and almost impossible to find a good set of 1100 ones as they have the most lift and thusly wear the fastest, often dead at 25K miles. Same with pistons, they can look great and the ring lands be oh so dead. I'd be checking out the top end wrist pin holes in rods as well, they commonly wear to be loose too.

Hope you are not mixing up all those parts-you pretty much MUST keep every single part reused in its' original location. I use marked ziplock baggies for the individual valve/tappet assemblies.
 
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