kz750 4 starter clutch

Greeting from a new KZ owner. I recently aquired a nice 1981 KZ750 LTD that seems to have a bum starter clutch. With the help of the Clymer book and some of your posts I have removed the clutch. I got a different clutch on ebay and installed it with the same results:angry: Basically the bike will turn over a couple of times then the clutch slips on the big gear going to the starter. I pulled the plugs and turn it over and it doesn't have any problem turning, but as soon as there is compression it slips.

So now the Question. Is it more likely that both starter clutches are bad or that there is another problem I'm not considering? I don't have a dealer near by, where might I find the kits to rebuild the clutch?

Thanks

You may have other problem than starter clutch, but my first thought was wheather you bought the replacement clutch brand new from ebay.

Before I replaced my, I knew a guy that only replaced springs and rollers, and was slipping two months later, so I decided to buy the entire clutch and hub, brand new to do the job. When I inspected the old one, could not find anything wrong to the naked eye. The new one worked just fine.

Another thought would be checking your engine compression. It there such a thing as too high compression?? What about starter motor, or gear??

did you replace "The clutch" or "The starter clutch". two completely different things. pretty simple systems, if the starter clutch housing is not broken and the springs and rollars are in good shape it should work.

I was wondering the same thing. I've never seen anyone sell a starter clutch on ebay. To replace the starter clutch parts means major dissassembly, removing all the transmission gears ect to get to it. Best done with the engine pulled out of the frame. If you didn't do this you were in the wrong "clutch" and you'll need to.

Thanks for the responses so quickly. I should have specified the starter clutch. I have removed the second shaft completely to gain access to the starter clutch (by the way it's a little tougher, but I left the engine mounted.) The best way to describe my problem is that the starter cluth acts like the clutch on a cordless drill when you reduce tension and hold the driver. It makes a similar noise and skips. Here's why I think it's the starter clutch: I pulled the plugs and put oil in the cylinders to lube the rings and with the oil pan off I lay on the ground and press the starter button for a second or two. The starter turns the large gear for a second then the gear continues to turn, but the starter clutch (assembly) skips and wont turn the belt that is supposed to turn the crankshaft.

Hope that makes sense to someone besides me:whistle:

Also, the starter clutch I bough on ebay was not new or rebuilt but it came from a "running bike". Kawasaki shoulda put a kick start or compression release on this bike and saved a lot of people grief!

KZrookie23 wrote:

Thanks for the responses so quickly. I should have specified the starter clutch. I have removed the second shaft completely to gain access to the starter clutch (by the way it's a little tougher, but I left the engine mounted.) The best way to describe my problem is that the starter cluth acts like the clutch on a cordless drill when you reduce tension and hold the driver. It makes a similar noise and skips. Here's why I think it's the starter clutch: I pulled the plugs and put oil in the cylinders to lube the rings and with the oil pan off I lay on the ground and press the starter button for a second or two. The starter turns the large gear for a second then the gear continues to turn, but the starter clutch (assembly) skips and wont turn the belt that is supposed to turn the crankshaft.

Hope that makes sense to someone besides me:whistle:

Also, the starter clutch I bough on ebay was not new or rebuilt but it came from a "running bike". Kawasaki shoulda put a kick start or compression release on this bike and saved a lot of people grief!

See the problem is, your bike is too new! All old bikes have kick starters...

Joking aside, I looked at the parts diagram and frankly it doesn't show me how it fits into your bike. On my '78 kz1000, the starter clutch is part of the rotor and lives behind a cover on the left side of the crank. I'm assuming yours is a friction based setup like mine is. So, if the springs and rollers that are part of the clutch are in good nick, then the shaft that they grab must be galled. In my case that would be the end of the crank itself, I don't have any chain/belts as part of the starter.

As an aside, if the battery is low and its not turning the starter clutch fast it may not grab properly, thats just a guess though.

Hope this helps...at least a little!

ok you got the right one. inspect the starter clutch housing carefully for cracks, they sometimes like to bust. it that is good i would search down some new springs and rollers and install those. i suspect the one you got is worn out just like you old one.

If the starter has a built in planetary reduction like the twins have (and I imagine it does), it just might be the starter that is causing your problem. Sometimes the ring gear inside the starter will spin instead of the output gear, so you hear the starter spinning but the motor doesn't turn over.

I'll have to give some thought to how to check and see if that's the problem.

Also, You did not mention if your engine is running well otherwise. If you can turn your engine easily by hand, on the right side of the crank,CLOCKWISE, without removing the plugs, then your starter motor and clutch should also be able to do so.

So far, it sounds like the second starter clutch was no good either. Am not saying you should do it again, yet, but, If I was to try the job again, would buy a brand new whole one. I know people say only do rollers and springs, but the hub could also be worn. I believe, this is one of those parts best not to buy used.