HELP! - 1981 KZ750(E1) Starter Clutch Issues

YES, the pan is off so we can see them turning. The starter clutch gear turns for a bit, then breaks free and you get the "clicky whirly" sound of it just rubbing... .

When you say the big gear breaks free do you mean it turns faster? Or do you mean it stops?

If it stops, then it would be the starter output shaft not turning.

If it turns faster, then its the starter clutch. In that case I wonder if a later zr750 starter clutch would be better, if its swappable. Daftrusty might have a post about it.
EDIT: It was WeeZee's post but Daftrusty did chime in about some details.
www.kzrider.com/forum/2-engine/607684-kz...h-solution-zr7s-part

I unfortunately didn’t do a write up on converting to the zr-7 sprag clutch because I neglected to take any really good pictures of the process.
But if you scroll down to almost the bottom of the page I briefly go over it in my build thread.
kzrider.com/forum/11-projects/602462-kz750e-resto-mod?start=40

I happened to buy both the starter clutch and the secondary shaft together. I’m not 100% positive, but I “think” it is totally possible to put the zr-7 clutch on the kz750 shaft. BUT....you will need to pay attention to the thickness and position of the washers that space the clutch on the shaft.



The zr-7 shaft is only different than the kz750 shaft in that the gear to drive the oil pump is wider on the zr-7 shaft. That is why I think one of the washers on the zr-7 is thinner. I think you can use the kz750 washers (both are identical) and will be fine. But once you install the shaft, torque everything down and make sure the clutch spins free and locks up when it should BEFORE you put the oil sump on. (I accidentally swapped the zr-7 washers around and it bound up solid when I torqued the secondary shaft nut tight.)
You will also need the matching starter clutch sprocket as they are not the same as the kz750.

There are usually 3-4 zr-7 starter clutch assembly’s for sale on the auction sites, but oddly enough not today. DO NOT buy one from a Zephyr zr750 as they are the exact same old style that you already have.

Hope this helps!

Hi all!

Thanks again very much. I guess i'm not 100% what to do now. Not really into just continually buying parts. I've done that, it hasn't worked

That is, I will need to link up with Uncle to see if the gear itself doesn't have grip, or if the tension, per one of the replies, was done correctly ( and how to adjust that, I've no idea).

But then, yes, perhaps if I can determine the PARTS are faulty, I can look into buying a new ZR-7 Starter Clutch, but that to me is kindof a last ditch option. Would LOVE to get it "grabbing" with what we already have, but I won't see uncle until Monday to try to examine the issue based on what i've read here.

Might have to tear it apart again and see if the gear is used or new. I replaced the housing that holds the pins, springs and roller too but am not saying you should. Thinking a new gear is a must though. Also replaced the needle bearing on the gear thinking it might hold it a little tighter?? (Only 10 bucks more) Not really a way to set tension on the springs. .. just install em and go. Have had exc results on mine...... hoping you figure it out.

It's probably worn inside the starter clutch housing where the rollers move. I saw a thread on here a while back where this was the problem after replacing everything else.

As far as I am concerned, when it comes to starter clutches, is best to replace the whole thing. including the inner race. Not parts of it. It is simply too much disassemble to take any chances. I did a Zephyr 750 about 9 years ago, replacing it whole, and never looked back. I had heard too many histories of people who only changed rollers, springs, or outer casings to save money, to only do it again as it starter slipping shortly after.

Look anything like this picture? HAHA.

Anyway, thank you. Honestly, if that is a known cultprit, i'm happy, as that means I know have hope, so long as I track down the part!

So I guess i'm 75% there!

I think I only have this old part...everything else is new (rollers/pins/springs and starter clutch gear).

Was there another part of the "complete" system that I'm missing? Thanks again!

Working on the bike again tomorrow, will shoot you pics. Thanks again!

Thank you, will be checking in tomorrow after I work on it again!

As i'm about 75% new parts at this point ( I think only the rollers/pins housing could be upgraded at this point), I think i'll try to hold off messing with a ZR-7.

But, this was supremely helpful, and what I will use next if my current plan doesn't pan out !

Thank you!