Cam chain master link shifting location upon rotation

[Spargett]

So I installed my new cam chain a while ago. It was quite a pain fishing to get everything aligned correctly for top dead center. Took a few tries before I nailed it, then popped the master link on (clip facing away from the the rotation).

Afterwards, I rotated everything around a few times and noticed that the master link's location would move two teeth down every full rotation. Perplexed I continued to rotate it around and watching it move over two more teeth every time. Doing the math it'd come back around TDC after x rotations due to x amount of teeth.

Even though the chain was tight at the time, I just didn't realized that was prob because the tensioner wasn't on. Possibly this was allowing the chain to move teeth even with the slightest amount of slack.

At the end of a very, very long night I bolted the top on, the last night I was able to use the garage.

I'm wondering why exactly the MASTER LINK has to be in the exact location over the cam sprocket's corresponding TDC to the pistons. It seems like the main purpose is to align the cam along with everything else.

Do I need to pull the engine and fix this? Alot of theories spinning around my head right now. I'd love to hear from voices of experience. I'm really curious to hear what you all have to say.

I have a feeling this may be one of those seemingly frequent reoccurring instances where I learn a lesson the hard way. Though, naturally I'm hoping not.

[G-Man]

Scott

Providing the chain has not jumped the sprockets, the difference you are seeing is that the number of links in the chain is not divisible by the number of teeth on the sprockets. Providing you still have the cam and crank in sync, it doesn't matter where the link is, except for the important moment you need to assemble or split the chain.

The reason you put it at the top of the cam sprocket on assembly is so that you can get to it. The 'sync' position will come around every two revs of the crank, but as you have discovered getting cam, chain and crank back to the set position is a rarer event.

Providing you can get the crank and cam aligned every two revs you are good to go...

You should try this with Triumph timing gears - you'll go gray overnight with worry....

G-Man

[Spargett]

Hah. Excellent. Thats pretty much what I was thinking, but I've learned very quickly... there's alot I don't know and thats bitten me in the rear more than once, even with logic on my side.

I've heard things about working on Triumphs. Sounds very testing at times. Not to say I haven't gotten a few grays on top of this 26 year old head from this gal ; ) Thanks again.

Scott

Providing the chain has not jumped the sprockets, the difference you are seeing is that the number of links in the chain is not divisible by the number of teeth on the sprockets. Providing you still have the cam and crank in sync, it doesn't matter where the link is, except for the important moment you need to assemble or split the chain.

The reason you put it at the top of the cam sprocket on assembly is so that you can get to it. The 'sync' position will come around every two revs of the crank, but as you have discovered getting cam, chain and crank back to the set position is a rarer event.

Providing you can get the crank and cam aligned every two revs you are good to go...

You should try this with Triumph timing gears - you'll go gray overnight with worry....

G-Man

[G-Man]

Hope that allows you to sleep.

Triumphs use a 'hunting tooth'. i.e. one of the idler gears has an odd number of teeth on it so that the wear on the gears is spread out. This also means that the quick way to check that you have everything right is to turn the engine backwards to the the set point.

Your project is looking really nice and your posts on here make excellent reading. I have restored many bikes over the years but have just got started on a CL77 (and a CL72 I felt sorry for). I would love a CB to do sometime but they come up very rarely in the UK.

Have fun!

G