I have one of these

http://www.piersideparts.net/CB1913.html 

Why the hell does it bind up hard on the case? The threaded hub part is about 3mm too short??

Cheers
Mick.

It binds up because..... The threaded hub part is about 3mm too short.

Smart ass. I'm asking why the threaded hub part might be shorter.

you might need some of these http://www.cbperformance.com/ProductDetails.asp?ProductCode=1915 

That sucks when things don't fit first time..! Time to make a spacer

It will throw the balancing out if we make a spacer, gotta go over the key. But if I get another pulley it'll probably throw the balancing out too.

Has it been machined?

No, not machined according to rod it might be a dodgy pulley but it should still work. He's told me what to do. Will give it a crack.

That's the spirit,

Stanley, I think they are gonna try crack, then they won't give a shit

The sand pulley kits come with washers, with a cut out for a key way. This is to space the pulley away. THey are light.

Given the small mass and small OD, i would imagine it wouldn't have much influence on the overall balancing of the system, but none the less would minutely. But given the same scenario on the other side of the crank, does one balance flywheel shims for end float setup?

(Update: Just had a call from Craig of Crankshaft Engineering for my bit of kit. Yes it will make an influence on balance, will you notice, no. Its no problem.)