Starter clutch problems..

Hi,

I just bought a KZ750 imported from USA to Sweden.
Bought it with the known error that the starter motor doesn´t crankt the engine.

Would like to ask you some questions before i pull the engine apart.

The sympthom:
When I press start on the button the starter motor starts running but the engine does not crankt over.
The starter motor runs on very hi revs, nothing seems to be conected to the starter motor. I pulled the starter out and tryed to rotate the spocket (that conects with the starter) with my fingers. It rotates freely anti clockwise and I can only move it 2-3 millimeters clockwise before it stops.

Questions:

1. I have no history what so ever of the bike. Can the starter clutch get stuck in disengaged mode due to long time no running ?

2. There is no or very little oli in the engine. Can this effect the perfomace of the starter clutch.

3. Can I some how tap the engine and hopfully get the starter clutch to engage ?

4. Can the problem be something totally different ?

5. Should the sprocket behave like mine when I try to move it with my fingers ?

Looking forward to some guidance

Regards
Arnold

Post edited by: Arnold, at: 2007/11/23 08:51

Post edited by: Arnold, at: 2007/11/25 12:23

Welcome to KZr Arnold.

The symptoms you're describing most certainly sound like starter clutch issues.
The starter clutch doesn't actually stick in a disengaged state, the springs loose their tension and/or the rollers break, which ultimately prevents the starter clutch from working.

Since the KZ750's were loosely based on the KZ650's, I'd assume the starter clutch is similar/the same.
If this is true, there's a real good detailed write-up with pictures in the archives on how to rebuild it that was posted by KZr member OnkelB.

The good thing here is, the engine does not need to be removed to facilitate the starter clutch removal.

Thanx Retro,

Did some more testing today.
When I rotated the flywheel the oposite way manually and then engaged the starter motor I sometimes got the clutch to grab and crank the engine.

But I guess I´m better of pulling it all out and change rollers and springs.

Your right, it is the same starter clutch reno kit for the Z650, GPZ´s and the KZ750. They all use the same type of starter clutch. Found out today that even the old Hondas and Suzukis use the exact same reno kit.

Is there really people here that have done this without pulling the engine out ?
Red something about doing dental work throw the but

Arnold wrote:

Is there really people here that have done this without pulling the engine out ?
Red something about doing dental work throw the but

I've read the same thing about the rectal dentistry trick, but I hear it requires a LOT of "knock out" gas! :blink: :woohoo:

Yep, OnkelB did the rebuild and the write-up on the procedure.

Here's the link to the archived thread:
Starter clutch fix

If you said, there is little oil in the engine, by all means, drain it, change filter, and refill.

The KZ750 was basically a KZ650 with a factory big bore kit. Starter clutches are same.

I have replaced starter clutch in my 750. Replaced the whole cluctch not just springs and rollers, as the hub can wear also. Did it with engine in frame. My bike is a Zephyr 750 so I had Haynes, and Kawasaki factory manuals to help me along. Needed impact wrench to handle tranny clutch bit nut. It is very, very, very tight. Impact screw driver for secondary shaft right holding plate. Considerable amount of disassemble had to be careful, organized, slow and deliberate.

If you have questions, let me know.

Post edited by: hugo, at: 2007/11/24 09:53

Post edited by: hugo, at: 2007/11/24 09:55

Post edited by: hugo, at: 2007/11/24 10:00

Hi again,

Well...I pulled my rubber gloves on all the way up to the elbows and went in through the "back door". After some mowning and screaming I finally got the starter clutch out. :sick:

Was really happy to see that two springs were missing and the third one did barely push out the roller. This means that I found the real cause of the problem. Yeehaa..!


My best friend during the disassembly was without a doudt the impact screw driver. (dont even try to do this without one)
Bought it today and cant belive that I havent thought of this excenelt tool before. Got all the philips screws out with it. Even though I messed some of them up, they all came out.

The clutch basket nut came out after wedging a steel bar in the back wheel and pulling the nut loose with my biggest wrench.

Now I´m waiting for the lokal dealer to get the reno-kit with new rollers and springs that I ordered.
Then I´ll let you know how part 2 of this story will come out.



Post edited by: Arnold, at: 2007/11/24 18:48

Will post some more pic..
See next post..

Post edited by: Arnold, at: 2007/11/24 18:57

Pulling out the starter clutch with the engine in place.

No springs in the starter clutch.

Post edited by: Arnold, at: 2007/11/24 19:08

I'm glad to see that you located the prob and have it removed for rebuilding.

Now the big question is, where did those missing springs end up? :S
I'd suggest dropping the oil pan to see if they ended up there. This will also give you a chance to see if there's anything else from the engine (cam chain guide, metal or fiber "shavings", etc) that may have worn/broke/came loose and dropped into the oil pan, and you can also clean the oil pump screen to ensure proper oil flow.

When taking a closer look I saw that two of the plungers still sat inside their sockets. They were pushed in a bit so it looked like they were missing at first. I was confused as well, just as Retro said, about where the springs and plungers might have ended up.

Next problem: How do I get them up ?
After scratching my head for a while and messing about with a needel trying to pull them out...I got an idea. Compressed air !

The first one poped right out...but the last one did not move a all.

The last one required a different strategy. I filled the socket (with the plunger and spring inside) up with oil. I cranked my compressor up to 10 bars of pressure and pressed air in through the little hole at the backside of the socket. It shot right out !
He..he..was quite impressed with myself there

Regarding the oil pan I found two plastic bits approx 25 mm (1 ") long. Maybe these came from the time cain guide ?

Arnold wrote:

Regarding the oil pan I found two plastic bits approx 25 mm (1 ") long. Maybe these came from the time cain guide ?

Sounds like it just might be the ends of the cam chain guides, since they're notorious for breaking off due to age, mileage and/or abuse.
If you can post some pics of those pieces, I guarantee that someone here will be able to positively identify them.
With the ends of the guides broken off the engine will still run, but the guides will probably be fully extended and not placing the factory spec (I'm not sure what that spec is) of tension on the cam chain.

I've heard of other members here tearing the motor down on their bikes to "freshen it up" or bore it out, only to find broken/badly worn guides or rollers. Oddly enough, the bikes were still running OK at this point.

If you've got the money and the time, a thorough tear down and inspection couldn't hurt. This will give you a chance to become incredibly familiar with your bikes engine, and leaves the door wide open (time and money permitting of course) to drop in an 810cc kit and some GPz750 cams. :whistle:

Post edited by: RetroRiceRocketRider, at: 2007/11/25 12:47