top end reassembly) how do i tell if sprocket is centered ?

[e3steve]

Christ. Talk about turn simplicity into rocket salad! Ed couldn't have explained it any simpler, IMHO.

BTW, speaking of simple: have I been a numpty? I mean, has anyone posted this cam sprocket nut solution before?

[Airmun]

I think you are looking for a problem that does not exist. Assemble it per the book and all will be well,have no fear!