Getting a rap/bang from somewhere .. Doesn't seem to be timed with valve train or any part of motor. Stops when at idle .Very intermittent.. once ,twice sometimes three times and then stops for a bit. I've gone over every inch of bike several times thinking I had something loose and was blowing in the wind. Pulled clutch cover and primary viewing plate checking for a bolt or nut bouncing around. Nothing. It does not appear to have any effect on power.. if I can use that word on a 32 y/o motor that's never been tweaked or opened for that matter. Any suggestions?

 

evey once in a while we get a motor that is doing just that < now i am not hearing what you are But - we have found this / while driving it bring the bike up to 35 maybe 40 in 3rd gear and find the spot that its not pulling the bike nor is it in a desell slowing down - the engine loose spot that keeps the revs up and not pulling the the bike but maintaining that speed - see if it knocks than -- if so the rear rod crank pin area on one side has a worn spot into the pins hardness and it will rattel when you drive it like i posted - jz

 

I'll give it a shot .. Thanks

 

Simple fix ... The @#$%% drive chain was loose and slapping in the starter housing. Put new shocks on the day before the noise started .. The ones I took off were compressed 1/2" shorter due to age .. Not sure it that affected it or I just didn't keep up on the tightness.. either way ...done deal