Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board BSA B44 Rotor Bolt Isn’t Flush

Hello. Another question for you all as I reassemble the bottom end on my ‘68 Victor 441 project. The nut that holds the alternator rotor onto the crankshaft will only go about halfway on before it stops. I’m pretty confident the crankshaft sprocket is all the way onto the splines and that the rotor is flush with it. Am I correct in assuming it isn’t right to have this nut hanging off the end of the crankshaft? Any suggestions? Thanks!

https://flic.kr/p/2o3HoFK

Where you need to look is behind it? That nut only holds stuff in place......but stuff's gota be in the right place.

My answer to your question is "No sir, that nut in the photo isn't right"

Has part of the threaded stub been cut off?

Something else I noticed: The parts fiche calls for a Lucas 54213901, but this is a 54212006. Is it possible this rotor is too thick for the crankshaft, or were they interchangeable? Tolerance between rotor and stator is correct per manual spec, so diameter is good. Thanks!

Yes rotors come in different widths
And Yes the nut is totally wrong

nut should look like this

The rotor should be about 1.35 inches wide based on what I have in the shop. The shaft end does look a bit sawn off.

Gordo

I'll try to be a little more helpful. This is a ragged out B50 but this measurement should be close enough.

Is the shaft key set correctly? If not, the rotor may not go on all the way.