Cam Chain Jump At Idler Assembly

Just put my 73 Z1 Head back on and while rolling the motor over with the kick starter I notice a slight jump in the cam chain tension between the intake cam and idler assembly. I originally thought the cam timing was off a tooth, however have double and triple checked it and it appears to be correct. It's almost like the chain and idler assembly get out of sync after the chain travels 3-4" or so. It doesn't appear to be normal - at least I never noticed it the last time I reassembled the bike- can anyone suggest what this might be? Possibly chain stretch? - The bike has less than 10,000 original miles....

thanks,

Rodney

Did you put the tensioner in and adjust it? If the tensioner isn't in it will let the slack jump from one end to the other.. HTH

Yes - the tensioner is in and adjusted.

thanks,
Rodney

Rod, something I've noticed in "playing w/cams" (installing/degreeing/et;all) is that after lobes go from depressing rockers/buckets to returning, valve spring tension/resistance goes from pressure against rotation to pressure attempting to continue rotation (valve spring force against lobe.) This is normal, & will cause a slight difference in cam chain tension depending on lobe orentation. though if chain & tensioners are all proper, there should be no discerible difference in chain path/height. Hope this helps. G

thanks gane - again it could be normal and I just never noticed it before - I did replace the valve springs when servicing the head so they are new (and strong) - I ordered new dampners for the idler and will replace them this weekend to see if it makes a difference. I can't imagine the chain is stretched at less than 10k miles....

appreciate your response- rodney