KZ1000 front sprocket.

I measured the lock washer I have and it has a 20mm hole with a 36mm outside diameter. I measured the nut and it is 32mm flat side to flat side. That's just 4mm to bend up onto the nut to lock it in place. That's not much. Seems like on everything else I've ever worked on had a lot more material to work with.

Do you torque the nut too? I notice it is looser after a while on the bike.
Steve

Normally yes, this time around the local shop put that sprocket on, but I would assume they torqued it correctly. It looks like they did in fact put on a new lock washer but did not bend it up onto the nut. My whole issue is that there is not much material (4mm/2 = just 2mm!) to bend up onto the nut to lock it into place. Every other bike and ATV I've worked had the same style lock washer and they always had enough material to bend up onto the nut so that the edge of the washer went almost to the top side of the nut. I guess I will go talk to the guys at the shop on Monday. I was hoping for some way to fix it today and get out for a ride.

The book says torque the nut 100 ft-lb for the 900 and 60 for the 1000's. I've been doing it at 70.
Steve

For anyone that may be interested the answer to the issue is to use red loctite. I may try to fold an edge of that washer onto the nut. There's only 2 mm, but it couldn't hurt. I put on the red loctite and torqued it to 70lbs as suggested by Steve.

on my kz1000 I use the bigger nut and counter shaft spline washer the tabs fit up the sides of the larger nut and is held in place with the shaft splines just be sure to count your splines for your application Z1 E has them 79-80 kz1000 Engine-page 5 about half way down

www.z1enterprises.com/lock-washer-counter-shaft-sprocket-3.html

www.z1enterprises.com/front-sprocket-loc...13-tooth-spline.html

www.z1enterprises.com/front-sprocket-loc...12-tooth-spline.html

Good Fortune!

TheTrout wrote: For anyone that may be interested the answer to the issue is to use red loctite. I may try to fold an edge of that washer onto the nut. There's only 2 mm, but it couldn't hurt. I put on the red loctite and torqued it to 70lbs as suggested by Steve.

I never liked the fact there are so few threads on that nut. In the past I've had them loosen and ride on the inside of the cover. Because of the way it's made, I haven't lost one and it must be one hard SOB. I've thought about using one of the locknuts from the clutch basket but I doubt there is enough threads or room for one.

Each time I have checked it, it was loose. 100 ft/lb seems excessive but there is a lot of strain on it. I might try the blue next time. I have some red, I just don't like the idea of using heat and possably losing the temper on the shaft and nut.
Steve

Hi there All,

My very first post - super stoked, but also super bummed. I have fallen in love with KZs and cannot wait to get going on this bike - everything is exciting, as I know very little about KZs.

So, I recently purchased my 1977 KZ1000 LTD and had my brother drive it home (as I live in Japan). On the way home the front sprocket fell off (at roughly 55mph) and locked up the rear wheel. Thankfully he's OK.

But the bike seems to be OK, save the frame (see pic). I had my good mechanic buddy check to see if the output shaft was bent/moved up and down - thankfully NO! A small amount of fore/aft movement, but nothing to be concerned about.

My concern lies with the frame/swing arm obviously, but also about the rear tire... it actually seems (via the pics) to be OK, but I am wondering is there anything you experts (saying this humbly) would caution against/offer advice on how to go about repairing this so I essentially do not have the problems again?

How should I go about button up the frame/swing arm?

I found this beautiful site, and will order the necessary parts soo, but want everyone's opinions and advice first please!!

www.z1enterprises.com/motorcycles/Kawasa...in-sprockets-z1.html

Also, I cannot seem to find a consensus on which sprocket sizes to go with - am I correct in researching/understanding that the stock sprockets are FRONT:15t REAR: 33t?

Sorry, I am new to all of this, but still super stoked to get crackin on this thing! Very much looking forward to the help!

Mucho thanks in advance!

Frame damage in 3rd photo looks bad and difficult to get at without removing swingarm and possibly also motor.

Hopefully a frame expert will be along soon. If not then start a new post.

Congratulations, that is a nice looking bike. I am glad your brother is ok, that could have turned out much worse.

Based on the chain disaster and all the junk behind the sprocket cover, I would suspect that much or all of the routine maintenance has been ignored. Once the frame is fixed, you will want to carefully do all of the maintenance.

Like JR, I suspect the engine will need to come out.

Never ride a bike on which the road-worthiness has not been confirmed by you or someone mechanically qualified that you trust. Even if the PO "promised" the bike has been "serviced" and is ready to ride, there is no substitute for performing due diligence as to safety & readiness. Brakes first, always; before you make it go, make sure it'll stop. There's no telling what some past Bubba has done that may be hidden from sight. Your brother was fortunate.

MGK612 wrote: ... the front sprocket fell off ...
Judging from the condition of the teeth on the rear sprocket, the entire final drive system ( chain and sprockets ) was likely far past service life. Was the chain checked for "stretch" prior to riding the bike?

... check to see if the output shaft was bent/moved up and down ... A small amount of fore/aft movement ...
There should be essentially zero slop in the output shaft. Running a chain too tight will damage the output shaft and/or bearing, leading to radial play. While the motor is out during frame repair, we suggest the output shaft and bearing be checked for damage.

My concern lies with the frame...
Indeed. Your concern is well founded.

How should I go about button up the frame/swing arm?...
A welder who understands frame welding and the effects of welding heat on frame strength should be involved in this patch.

Good Ridin'
slmjim & Z1BEBE