1980 Kz750 LTD dreaded starting noise

Hello guys, just rebuilt my starter clutch and my bike is still making this dreaded grinding noise. Is it my starter?

Sorry thought I had attached a video to demonstrate the noise. It should be there now.

Thanks

Hi,
Your video link doesn't work...

One of my 1100's makes a horrible loud grinding - gnashing metal noise when cranking. The previous owner said it had always done that in the 10K miles he put on it. I've never had a problem with starting the engine, but it sounds like impending mechanical doom. The noise stops as soon as I release the starter motor button or when the engine starts. Because I very seldom ride that bike, I've only tried to swap out the starter motor to find the problem so far, but that didn't get rid of the noise. I know it isn't the starter clutch. My hunch is the reduction gearing and / or the starter ring gear are the problem....maybe the thrust washer is missing or installed incorrectly on the reduction gear, or the gears aren't properly aligned and are interfering. Maybe the short reduction gear shaft is worn or loose in the case and cover....all things you (and I) should investigate....buy another gasket and take the cover back off....look at the parts diagram (on Partzilla or Bike Bandit) to compare what goes where with how your bike is....

I posted a thread about starter noise on the 750 a couple years ago. My bike makes sort of a squawking noise, and based on feedback from other users here it seems this noise is fairly common. As long as the starter spins I'm not going to do anything. Guess it's a matter of degrees though.

I replaced both the complete primary clutch assembly and the gear with NOS- replacing just the rollers or springs seemed risky to me. IIRC there are some quality issues with pattern parts

The sprag clutch tends to get dents in the housing, meaning it doesn't wedge reliably.
This is exacerbated by synthetic oil and a weak battery.

This is the £25 ZR7S fix:
www.kzrider.com/forum/2-engine/607684-kz...ion-zr7s-part#777466

Hey I used to have that noise on my 75kz400. Even got as bad as spinning without engaging the starter + the noise. How I fixed it was pretty simple. The starters on these (or starters in general) are fairly easy. I took mine apart (carefully noting where the washer shims go, etc). On mine, theres only one lead that needs disconnected to the brushes. From what I see (Ive redone my 75, 76 and 77 starter now) there is a yellow haze that forms on the metal connections, causing poor connection (and that horrible sound). This may sound cray, but I simply put the pieces of the starter in the parts washer and scrubbed everything (yes everything). I did take extra care not to soak the main spinning coil part. I dried them very very good with an airgun. (pretty important obviously). Then I took some fine sandpaper and cleaned all the plates and end of the brushes. Let sit overnight. Next morning, hit all the parts again with the airgun to make sure there is no more liquid hiding somewhere, and put it back together. Hooked it back up to the 75, and the sound was gone. As I mentioned I did this to two more identical starters since, and all 3 had that nasty sound/issues with engaging. Now all 3 work like they should with no problems.

I also did this to my 81kz440, and its working great now.