Airhead duplex cam chain problem

[Rob Farmer]

Came across a problem yesterday while I was trying to fit a new duplex cam chain in my R100 RS. I took the engine sprocket off and pulled the camshaft out, fitted the new cam chain and tried to put it all back in. With a bit of effort I got it all back in place but the cam chains so tight it's almost impossible to turn the engine by hand. First impressions are that the cam chain is a link too short. It's a new one from Motobins.

Anybody else come across this before?

 

[ciderman gs]

count the links on the old one and compare with the new one or could it be that your old one was so worn that the new one is how it should be

 

[Tarka]

Just ideas Rob......

If the link count is correct....are you using the original sprockets and maybe they`re worn in such a way that the new chain isn`t seating properly on the teeth ?

How are you trying to turn the engine...off the sprocket bolt?
Plugs in...against compression?
Sure it wasn`t previously as difficult via whatever means you`re using?

Like I said,just ideas.

 

[Rob Farmer]

The original camchain was taken off 20 years ago so isn't around for comparrison.

I've taken the heads and barrels off to check out their condition so no compression to worry about. Without the chain the crank spins freely.

I'm sure the new ones a link too short. I was hoping somebody else may have bought a chain from Motobins and had similar problems.

 

[Bryn]

Rob, no expert ( as you know ) but on www.realoem.com I've just had a look and there's exploded diagrams of the R100RS engine bits... you could count the links on the diagram??

Just a probably crap idea but you never know

 

[Rob Farmer]

Any help always appreciated Bryn

I've ordered another cam chain from Motorworks this time so we'll see how they compare.