Folks is there a way to replace these chains without taking the head and barrels off? My manuals deal with this in the context of a complete rebuild. I guess the key issue is locking the engine how to do this effectively without inserting a bar through the small ends of the con rods? I noticed some wear on the magneto chain (back interior surface) Cam chain was a bit loose (top tensioner bolt has been grazed) I already have the magneto out (sent it off to be rebuilt). Any suggestions or solutions most welcome! binx

64 Atlas 70 A65L

With an impact wrench you can 1. remove the cam nut 2. then remove the crankshaft nut/oil pump drive gear (LH thread) Only on the odd ocassion will these be super tight causing a problem. I have always finally, been able to take them off. I think the nuts are british sized. You should be able to pull the gears off with the chains. If it is not boogered it will come off fairly easy. Otherwise you might want to use a very small jaw puller to get the cam sprocket off. It is tough to get small enough jaws in there to fit. Screw drivers will mess up the face of the cases.