does anyone recognize the pounding sound

[T Legg]

My black 84 fj1100 is making a pounding sound most notable at idle.It has made this sound the entire two and a half years and eleven thousand miles I've owned it but I think its getting louder now.before I bought a second fj1100 I thought maybe the sound was normal since the bike runs great and has good compression. If I were deaf I wouldn't think anything was wrong with it but the new yellow fj i bought does not make this sound.the transmission of the black bike has a serious slipping second and third gear problem .I have planned to replace the transmission in the next couple of months but now I am worried I might have a bearing problem somewhere.I posted a video on you-tube of my yellow fj running which sound normal compared to my black fj which is making the pounding noise.the clackity clack noise of the black bike is from the plastic slides of the mikuni flat slide carburetors.     https://youtu.be/aI04gJL38mM      does any body recognize this sound?

[racerrad8]

Does it change when you pull in the clutch?

Randy - RPM

[T Legg]

The sound doesn't go away when I pull the clutch but it does quiet a little and definetly affects the sound.

[racerrad8]

Then starter chain slop & starter drive rubber cushions are as hard as a rock could make that noise.

Also, if there has every been a broken clutch basket or something got into the crankshaft teeth, that could be the course as well.

Randy - RPM

[T Legg]

thanks for the advice Randy.If I were to open it up to replace the transmission would I be able to see a broken tooth on the crankshaft and would I be able to change the starter chain at that level of disassembly.

[racerrad8]

You can see damage to the crank teeth and basket.

No,  the engine must be completely stripped to replace the starter and timing chains.

Randy - RPM