1981 KZ 440 LTD Belt Drive (late model) Belt Squeaking

A chirping noise started coming from the belt when the rear wheel spins, I think the noise is coming from under the Engine Pulley Cover. I previously noticed a slight rubber/metal rubbing sound when rolling the bike into / out of the garage (engine off), but (probably naively) thought it minor since I could not hear anything with the motor running and the belt has not shown any signs of wear that I can see. Now with the chirp (audible at highway speeds), I'm thinking my alignment might be off.

Using the string method, my rear wheel center-line tracks about a half inch to the left of my front wheel center-line. This seems like a lot, and the rear Adjusting Bolts seem to be dead on at the same length. Does this suggest the rear wheel spacing is off? Should I just try to use the Adjusting Bolts even if alignment is obtained with them not being in the exact same position?

On some bike the front and rear wheels are not in line. Some have the rear offset for chain (belt) clearance. As long as the lines of the front and rear are parallel your good. More important is the belt alignment. Look at the belt front behind the bike, it needs to run straight.

Do you know where in the service manual it would specify what the offset is? Thank you!

On a stock bike offset is not adjustable. It is set by the correct placement of the spacers on the rear axle.

kzrider.com/modules/ServiceManuals/kz440.pdf

Once the belt is properly aligned, the squeaking should stop.

Page 120 in that manual shows the rear hub. It’s chain drive, I can’t find any break down of a belt drive. Typically that would be reflected in the supplement section toward the rear. If it’s not called out as different then usually it’s not.

I can’t take credit for these screen shots, they are from another member “Patton”





Belt alignment is made by adjusting the rear axle adjusters.

I found the belt was looser than spec so I tightened the belt and (attempted to) fix the rear alignment using the belt adjusting bolts.

Initially, the left side of the front wheel measured 2/16th of an inch from the left edge of the rear wheel, and the right side of the front wheel was 1-4/16th inches away from the right edge of the rear wheel. I got it to 12/16ths on the left and 11.5/16ths on the right by adjusting the belt adjusting bolts. I also ended up tightening the belt to spec.

The ride around the block didn't make any noise. I did notice that with the tighter belt, the rear wheel is a little more difficult to spin by hand. Also, there is now a pull to the left side when riding no hands. Do you think this may be from the tires being worn non-uniformly from being out of alignment? I don't see a bend to the belt like in the photos (but honestly, I didn't see a bend before I adjusted the alignment, so I think bends are not that obvious on the belt drive).

I also did some more digging and couldn't find anything saying the 440 LTD has an offset wheel alignment. I'm pretty sure the previous owners did not modify anything on the bike, so I'm guessing the rear was just badly out of alignment, or maybe the frame or swing arm is bent.

Now that you have the belt aligned, look at the notch on the swinarm and compair them from the right to the left. They should be on the same alignment marks. That will confirm your alignment. As for the pull it could be a bad wear pattern on the out of alignment wheel. You should be able to see the wear pattern on the tire. Look for feathered edges. I’d say if the noise is gone you’ve corrected the problem. Cautiously ride the bike a while and see if the pull goes away. Use extreme caution and avoid any wet roads or rain. If the tire is worn it could be a very greasy ride. Give it time to correct

How did you check the tension on the belt? Did you use the dedicated tool?

If all adjustments are done and the squeaking continiues, put some candle wax on the belt/pully side surface.....

F64 wrote: How did you check the tension on the belt? Did you use the dedicated tool?

I did use the dedicated tool. But weirdly it seems like my tool stays at the upper liner (tight-side) no matter how much I tighten it. The manual does say to set it to the upper line, but I'm thinking I should go somewhere in between to be more safe since it is now making a sort of humming noise when I ride it.

I noticed that the rear wheel will turn very slightly before the belt will start to turn (maybe 1-2 degrees of wheel turn before the belt catches and starts to turn). Anyone know if this is normal or if I messed something up when attempting to fix the alignment?

Also, I found that my brake side rear mark is about 3 notches back while my belt side rear mark is about 4 notches back. Before I adjusted it, both were set exactly to the same point, just under 3 notches back. I'll try to take some more measurements but I'm thinking that the frame or swing arm may be bent.