Starter Bushes Destroyed in under 5000 miles?

Hey all, very confused about this and hopefully someone here can help me. When I first bought my '83 KZ750 LTD F1 last Thanksgiving the starter was dead so I rebuilt it using one of the kits on eBay, basically replaced everything except the casing, coils, and gears. It worked flawlessly up until the last couple weeks where some days it was fine and others it wouldn't start the bike at all and I would have to roll start it. It finally wouldn't do anything at all when I pushed the ignition switch so I tested the solenoid and found it was still good and then went to the starter and found the problem. The brushes had basically been turned to dust inside the starter and there is a groove all along the center of the commutator. Does anyone know why my brushes wore down so quickly? I don't have any problem rebuilding it unless I'm going to be doing it again in another 5000 miles or less. Were the brushes I got in the kit just low quality? Any help is appreciated, I have a local classic bike shop that I'm going to take the coil in to to see if they can sand down the groove along the commutator. And if anyone knows where I might be able to find another starter for under $300 should this one end up being unusable that could be potentially useful information.

Thanks!

Are you sure it's not turning with the engine?
Steve

As far as I know the starter clutch functions properly, that would explain the excessive wear though. Do you know how would I test the starter clutch to see if it properly disengages?

-- Nevermind, found out how to check it and everything seems to be working on the starter clutch.

Try eBay?
Steve

Dont know why the rebuild kit and replacement brushes would cause grooves in the commutator. Made in China perhaps?

Should be very possible to get a new starter for under $ 300.
Heres a site I book marked a few years ago
www.nationsautoelectric.com/Kawasaki.html Scroll down
I have never used them and dont know if still active.

This the commutator.

swest wrote: Try eBay?
Steve

Not a single starter on eBay that I've been able to find.

JR wrote: Dont know why the rebuild kit and replacement brushes would cause grooves in the commutator. Made in China perhaps?

Should be very possible to get a new starter for under $ 300.
Heres a site I book marked a few years ago
www.nationsautoelectric.com/Kawasaki.html Scroll down
I have never used them and dont know if still active.

I'm not sure where it was made, doesn't have it listed anywhere. And that site does have one for about $150 + $50 core, so at least that's an option. Thanks!

Wow, that thing is toast. :ohmy:
Steve

For sure
Nasty groove.
I cleaned out my starter motor a month or 2 ago. Carbon brushes could never do that damage.
Good luck with the replacement

Well that's disappointing to hear. Haven't had a chance to take it in to the shop yet, maybe tomorrow if they're open. If they say it's toast I may try throwing it on a lathe and just grinding it down so it's smooth and rebuilding it from there. According to the Clymer as long as the copper isn't down to the mica it's still good and assuming I'm looking at it right I actually still have a lot of material left.

There must have been steel making that gouge.
Steve

I thought it might be the springs behind the brushes but they don't extend far enough to make contact with the commutator even after the brushes are gone. I'm thinking it might have the been the wire that was connected to the brushes. I lost one brush before the others went and the wire from that one was just gouging the steel while the other brushes were still allowing the starter to spin. That's my best guess.