Starter clutch preventing high revving

I already know my starter clutch is out on my 1982 GPz750. It makes a horrid KKCKCKCKGHCKCHG noise when the starter button is pressed. However, I've tried push starting it really struggles.

I put it into second and pushed it and it seemed to start, but as soon as I pulled in the clutch again, it died. I was able to get it started and to run once, but even at full throttle it just wasn't revving up as high as it should.

My engines professor theorized that my starter clutch could be stuck, not disengaging when the bike starts. He said that could also be the reason it makes that horrid noise.

I'm going to start rebuilding the starter clutch. Is this the right way to go? Could there be something else holding the rpms back? Could that horrid noise be coming from something other than starter clutch?

That would definately be a good place to start, once you get motor to start/run then you can dignose other issues it may have.