Sprocket-cover cracked! Wy?

Hey Everyone

Today i finally got my '79 Z650 on the road, hooray! I went for a short run on some backroads (around 40 miles), and after around 30 miles I got a squeeky sound when I pulled in the clutch-lever, some times more, some times less. I decided to head home, and around 2 miles from home I pulled the clutch again, stopping in an intersection, and my sprocketcover cracked!! :blink:

Can anybody tell me what the f... is going on?



Pretty bummed right now, need to go hunting for a new cover or somebody with welding-equipment for doing it back up?

Ever cleaned and lubed the clutch rod throw out mechanism? It was probably past due for service, putting undue strain on the sprocket cover. I'd think if the cover is not to badly cracked, a local welding shop might be able to fix it for you, and there's always the salvage yards:

Motorcycle Salvage Companies
www.cycle-salvage.com
www.motorcycle-recycle-center.com/
www.newrivercyclesalvage.com/index.html
www.bornagainbikes.net/
www.motolane.com/
www.williescycle.com/

Well thank you, I think it should be cleaned and lubed up alright, but I'll have to have a look at it tomorrow.

Thanks again

GreatDane, that sprocket cover carries an unexpected amount of the clutch load. I've have seen the sprocket cover move when clutch is pulled in. It must be tight on all four retaining points, as the worm actuator pushes against this sprocket cover. You will notice also, that the cover has dowels on at least two of the retaining points to provide a solid base to push against the clutch springs.

It makes you wonder how good an idea it is to drill speed holes in it like some people have, possibly weakening it more.

Darmable: Exactly my thought, I don't understand how they don't break every other week.

Garn: I believe the bolts were evenly tightened, but off course, with this happened, I've been wondering about it too.

I finally got the time to pull the cover of today, I thought it had only cracked on the upper half, so I wanted to bring to a local shop that I use for other jobs (job-related stuff), that I believed could weld it. When I took it off, I found out that the bolthole on the lower front was ripped off too, so I think it's impossible to save now. The other thing i found out was that my pushrod was bend (the part that sticks out of the engine), and that the bearing-ball on the other end was worn flat, and in some way stuck to the end of the pushrod, maybe that's part of the problem?

Not maybe; for sure. You should get replacements for the cover, rod, and ball bearing, install, and adjust correctly using the manual as your guide. These things do not break or bend easily, so clearly someone goofed before when installing cover and adjusting clutch. Ed

Would seriously consider a roller bearing clutch pusher also. Had the same issue with my kz1000. When I bought it.

Ed: Thanks alot for confirming my suspicion, I'm pretty new to this so I can only look at what doesn't look right, learn as I go - nice to have a forum like this to be assured that you're on the right track. I've talked to the guy that I bought the bike from today, and he was almost certain that he had a few covers lying around, he'll phone me tomorrow.

2wheeladdict: Sorry, as mentioned above I'm all new to wrenching old bikes (or any bikes for that matter, used to be into cars). Can you explain to me more specificly what that is, how it works, where I can get it and such?

GreatDane wrote: 2wheeladdict: Sorry, as mentioned above I'm all new to wrenching old bikes (or any bikes for that matter, used to be into cars). Can you explain to me more specificly what that is, how it works, where I can get it and such?

+1

Where can you get one from?

had the same thing happen to a 900 years ago
the ball on the end of the rod friction welded itself to the pushrod
it the spins with the clutch
which turns the clutch actuator in the sprocket cover
and pushed the cover out til it cracked
it was my fault for over reving the bike
you gotta check the clutch side for damage as well

I am pretty sure I bought it from z1 enterprises. If not from APE. Instead of a friction contact against the clutch housing from the clutch pusher which causes the spin weld to bearing as mentioned above there are roller bearings on the face of the clutch pusher that spin and take some of the friction off the ball bearing and pushrod contact points. My parts were spun welded and sprocket cover cracked just as you described. Only have about 650 miles on mine since repair but absolutely no issues. Had to pull assembly out the clutch side to repair. Good luck.