Starter making odd sounds 2000 Busa Info needed

[Macfast]

I have a 2000 Busa with 28,000 miles. Starter Has not been modified. The starter sounds like it is not engaging will grind a little bit, then catch and start up.
I pulled the cover off an hour ago expecting the worst - everthing looks normal - I thought I would find teeth broken off but everything looks fine.
Tried the starter button with gear off - spins over fine with no noise. All teeth on all the gears look good, no visable cracks in case
Any words of advice ? What could be the problem?

 

[paulcee]

Try the starter clutch, there are shims all the way round the inside, easy replaced on eBay quite cheap

 

[dre_m1300]

Yea sounds like the shims. They usually starts acting up at around 25000 miles.

 

[Macfast]

Thank all of you, yes you are correct starter clutch among other things, also I thank Kevin at KWS for his advice

 

[normalcyispasse]

I had this problem with my '02 and it was indeed the starter clutch (sometimes the starter would engage, sometimes there would be a horrible awful clunk, sometimes a slight grinding noise). I purchased a take-off starter clutch on eBay for about $90, a printed gasket locally for about $10, and then of course did an oil change while I was in there. My total repair cost was around $130; total hours were about 3, though knowing what I know now I could pare this down to an hour pretty easily.

I did a write-up with photos during the repair; if you're interested, let me know and I'll post it.