my donor engine is beig built up by a garage. he has knocked out the old bearings to find them being 72mm outer dimaeter rather than 68mm as stated on every parts fiche he can find. anyone heard of an ar motor with a 72mm bearing? its definately an ar engine??

I haven't checked the exact outside diameters but I believe all were the same. Bored out to enable bigger bearings because of damage? You need to be very careful checking all dimensions if work has been carried out.

My AR bearings are 72mm OD. I know I have already sent you info so hopefully you are getting it sorted. Could your builder be looking at the CR rather than CRM? a lot of people have not even heard of the CRM and they are completely different bikes. CR is 68.00x28.00x18.00