HELP! - 1981 KZ750(E2) Starter Clutch is fixed, but problem isn't.

Hey all,

This forum has been of immense help to me during the past few months working on my bike. Hoping you all can come through again!

Basically, my KZ750 starter clutch was slipping. My Uncle (30 year mechanic, past 10 years predominantly Harleys, previous to that all Japanese bikes. Anyway, we tore the engine entirely apart thinking we needed to (you don't ), replaced the starter clutch assembly (clutch itself, springs, roll pins, rollers). Wasn't a total waste, as we cleaned, lubed, gasketized, and painted the engine.

I identified the parts (with your help!) on the Kawasaki bike. Unfortunately, it is now making the same noises it was originally. I've NO idea (nor does Uncle) what could be causing the rollers NOT to engage the starter clutch.

Guys, pleas help!

Ryan

Anyway, we were

Are you sure it's not the starter itself? Sometimes the starter can have internal issues that give the same symptoms as a slipping starter clutch. Maybe someone with more experience with it can chime in, but I think something becomes loose inside the starter housing and slips. Maybe it's the ring gear (of the planetary reducer). This makes the output shaft of the starter not turn.

Also, sometimes the starter clutch will still slip unless you replace the big sprocket (part 12046-1032) shown as 12046 on the diagram. After years of slipping, the boss on the sprocket can become galled or under-sized. There are good photos somewhere on this site on how they should look when new. When new, you will clearly see machining marks on the mating surface of the sprocket boss. If those are gone, then the sprocket may be worn too far. Usually it's the 750 twin bikes that have this issue more due to the much larger cylinders so you might have to search for topics on the 750 twin starter clutches to see some good photos.

This is only a partial diagram to fit on the page, but the full diagram shows two different starter motors.
Here's a link to the Kaw site, which you've probably already looked at a million times.
www.kawasaki.com/Parts/PartsDiagram/134887/1981/KZ750-E2

Here is the picture Loudhvx mentioned:

Not my picture but posted by some clever member of this site.


I also needed one of these sprockets but could not find one new from Kawasaki and new OEM ones on auction sites cost too much. That is one of many reasons I why I used zr-7 sprag starter clutch in mine. Details of which can be found in the link to my kz750e build in my signature.

Hey there!

Thanks for the help! I may have been unclear. I DID CHANGE the starter clutch (big cog), the pins, and rollers. And my uncle has tested the starter, and its working fine.

So, everything "works" and "turns", its just the starter clutch engages, and then disengages, and there is just "click click click click" of it slipping.

Please let me know if you've any additional ideas.

Thanks so much for the help!

I've already replaced that gear, the rollers, and the pins.

Could be a starter solenoid issue . You may want to try jumpering the solenoid with a screwdriver to see if the starter turns then. And make sure you have a properly charged battery.