Wrestled with my kickstart spring and sprocket for 15 minutes putting it in my lower case. No luck until I employed my vicegrips and snugged it right in. Easy.
I had the same issue last weekend mate, I'm rebuilding 2 CB750 engines ATM, and as my cases were already blasted and ready to go, I used the other engine that I'm stripping as a guide, which was fantastic, I had the whole transmission back in my cases in under 30 minutes.
There is a real technique involved in setting the kick starter spring and gear into the cases and then installing the shaft, but being able to look at the other engine's transmission made it easy. The other engine was in terrible shape, ruined crank and rods, shot bearings, bits of clutch plate in the sump pan etc, but what made me laugh was that the roll pin that holds the kick starter shaft in place was missing completely?
I'm guessing this engine died close to it's first start up after a dodgy "rebuild", so it was never tested, but if anyone had tried to kick start it, the shaft would have come out of the cases, and if the engine was running at the time, all hell would have broken loose inside. Some people shouldn't be allowed to own tools.........