Topic: '72 motor in a '78 cb750 frame sprocket questions

[specialone70]

I swapped a 72 engine into my 78 cb750 frame, it runs, and now I just need to sort out the sprockets. I'm a little confused about which sprocket I should use on the transmission: the 15t and oiler thing that came with the engine, or the 16t and bolt (no oiler) that was on the 78 motor/transmission. Next problem: Either sprocket will now be offset from the position of the sprocket on the 78 transmission by about .25" (if I recall correctly). Is that fine or will it mess things up trying to run like that? Last question: If I need to have the rear sprocket at the same offset, what do I need to replace to achieve that? Thanks in advance! You guys on this forum rule!

[70CB750]

CycleX sells just that, sprocket carriers to solve your problem.

http://www.cyclexchange.net/Chain%20Sprocket%20Page.htm

[754]

Just put a 76 or earlier sprocket carrier on it, along with the greasy spacer, probably. Have to add a spacer against the swingarm.  Then decide if you want to run 530 or 630 chain.

[specialone70]

Could I just stack a couple washers on the sprocket carrier studs?

[Retro Rocket]

Could I just stack a couple washers on the sprocket carrier studs?

NO, the 78K has a 10mm wider rear sprocket carrier so you'd have to remove 10mm, not add anything, the easiest way to fix it is to use an earlier up too K6 sprocket carrier and spacers as has already been said....