The pistons are NOS third over. The cylinders were honed just enough to warrant slightly larger pistons. I was very, very careful about the cam chain's installation; redoing it a number of times to insure it was correct, knowing how much of a pain it would be to fix.
I noticed as I rotated the engine one full rotation the master link would be two links "off" each time until eventually returning to top dead center. I was informed this was normal, but that was only from one person.
There's always a possibility that it could have been a human error. Though my memory says it was perfect. Would one link really have that drastic of an effect? Is it possible the cam chain tensioner was loose enough for the chain to jump a link?
Just thinking out loud here. Thanks again for the feedback.
teazer wrote:Scott, sorry to read about your accident. Riding two hours to O.R. with that damage. That's impressive. I dropped my wife's FZR400 the day I finished rebuilding it and complained for days about a few bruises. :-(
I am new around here but not to CB772's and I have to admit that I did not read all 35 pages of posts to see what you did inside that motor.
That noise is either a piston hitting the head or a valve smacking the piston. I had what sounds to me like the same noise in a motor with CB250 pistons. It was fine to turn over by hand, but fire it up and it made that noise. Motor out, head off, machine pistons slightly and sling it back together - 6 hours start to finish (with two arms).
It also sounds like a ton of tappet clearance, but that has been ruled out.
If pistons are originals or OEM replacements, I'd speculate that the cam timing is one tooth out.
Pop the top cover off and turn the motor over slowly and check cam timing first. While the top is off check the rockers to see if there is too much side play or anything else odd happening. With the motor on the bench and the top off, spin it over and see if you can locate the noise.
Pop the head off and look for shiny witness marks where things have been touching.
Teazer
