AJS & Matchless Owners Club

While checking my chaincase oil level today I noticed that the primary chain was to tight,e.g. hardly any play.As I have only done about 100miles since replacing the engine sprocket and re-tensionong the prim. chain ,I am at a loss as to how this has happened.The adjuster on my gearbox can only hold the 'box from moving forward,so I presume that the 'box has moved back while under the load of acceleration (!)Can someone confirm what the chain free-play should be,and is backward movement of the 'box controlled only by the mounting bolts being done up "real tight"?? Thanks,C

about 1/2 at the tightest spot.
common enough this, have you got the two nuts on the tensioner, one each side of the trunnion it goes through? goes some way to stopping it moving, but the nuts need to be tight; new paint on the engine plates don`t help if you painted them recently

A. There is always play in the adjuster eyebolt and in the stud itself in the engine plates.

B. In my experience the gear box will always move to the rear, which yours has obviously done.

So, adjust the primary chain from the tight position,ie. pulling the box forward, this takes out the play in a rearward direction so the secondary chain can't pull the box back.

Gawd, don't I waffle!

Thanks,both.The paintwork on the engine plates is fresh,and the adjuster is done up as shown,tight on both sides.When fitting the new engine sprocket I had to move the'box pretty much as far forward as it could go to get the free play as required.I will keep my eye on it over the next week or so,and hope it is just the bedding in process of the new sprocket.Thanks again,C. P.S. I never knew that motorcycling could be so involving and fun,some day I'm even going to ride the thing!