Is there a difference in camshafts and advance rods between years?

That could be a problem, as I mentioned. None of the 447 tensioners used a sprocket so I don't know where you'd get one.

5twins said:

That could be a problem, as I mentioned. None of the 447 tensioners used a sprocket so I don't know where you'd get one.

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Good point. Might need to change all the tensioner parts to 447 style. I do not know if it would be just a bolt in operation.
Somebody might know.

Was just looking at a 650F diagram of that wondering if outer bolt holes match up. That said, I'd also have to see if the tensioner mechanism, spring, etc I have works freely now it's cleaned up. I only remember it was snug/ tight in there after sitting for a v.long time. Umm, what would be the effect of that chain pitch difference using the "72 256 tensioner sproket. I have all of that in hand and the 106T cam chain fits the same in that tensioner sproket as the 447 cam sprocket the chain only hits the tens. sprocket where I believe it operates, the wheel pressing out so the chain slides on the back guide. If I try and make the chain go around the whole small diameter tensioner wheel, I see a problem. just having the chain use part of the tens. sprocket...like it should +- 5 teeth. L ooks OK to me. Or, am I fooling myself? See pic.

Check your cylinders' chain tunnel.

70-71 XS1s had a narrow tunnel with a bridge.
Gotta use a sprocket tensioner with those.

Later cylinders have the wider/open tunnel, and can use the slipper type tensioner...