kz750 rear axel

So I finally have the carbs mostly behaving but had noticed that the rear end of the bike was sloppy. Started out by discovering that there are missing spacers on the axel. Went to the hardware store and ended up putting in about 3\4' of thick steel washers just to get the wheel to fit properly in the swingarm. Now; however, if I try to fully tighten the axel nut, the wheel binds up and won't spin freely. I tightened it as tight as I could without binding, but it is still loose enough that the axel can move a bit under braking. Guess I gotta check out the parts diagrams to figure out the proper assembly and what is acctually missing. I'm really beginnig the hate this bikes previous owner....

You're right; you really do need to use the correct spacers rather than washers. Otherwise you may apply force to the outer bearing races or the wheel rather than just the inner bearing races. Also, you can get things misaligned if the spacers aren't correct. Here's the diagram for the KZ785--B1. Notice there are a bunch of different spacers/collars. Ed

ok...I cant seem to find anything missing but the wheel with all factory spacers (near as I can tell without a full disassembly) still is about 1/2 inch narrower than the swingarm.??? although the axel itself seems to be inserted backwards from the diagram.
Did figure out that as i was tightening the axel nut, I was forcing the brake disk into the piston causing the binding. Figured this out when the disk started rubbing on the brake mount..duh! Moved another washer into that spot and was able to get the disk recentered in the caliper and also fully tighten the axel nut without causing any binding. Still puzzeled as to why I had to add the extra washers to get the wheel spacing right, but seems to be corrected for now.

Is this a new problem after taking the rear hub apart or has it always been like that after purchasing the bike?

I would disassemble it & compare all of the parts to the diagrams. Assuming it's the stock wheel & stuff, but you never know what the previous owner did. eebbaayy photos can be helpful if unsure of something.

martin_csr wrote: Is this a new problem after taking the rear hub apart or has it always been like that after purchasing the bike?

I would disassemble it & compare all of the parts to the diagrams. Assuming it's the stock wheel & stuff, but you never know what the previous owner did. eebbaayy photos can be helpful if unsure of something.

+1 !

If extra spacers are needed something is wrong. I wonder if it is the correct wheel / swing arm combination or if maybe a previous owner swapped one or the other ( or both). Also, I wonder about the alignment of the sprockets if the extra spacers change the distance between the swing arm and the rear sprocket. Ed

Just an update on this.......and the stupidity of PO's

After checking everything I had confirmed that all the proper wheel spacers were there and in the correct order, but there was still extra space inside the swingarm, so I continued to ride after rearranging the ones I added to tighten things up. I failed to notice in my frustration with the general care and maintenance of this bike ( as well as my NEED to ride it) that I had burned off the entire right side brake pad in the caliper. Once I discovered that I parked the bike for a bit till I could get new brakes.

New brakes came in and I pulled the wheel to install them and discovered that the right side wheel bearing had run out of the inner race.

Turns out the simple things get you....Seems the PO had screwed up his axel bolt (probably beating it with his head or some other blunt object) and put in another one from a different year/model bike. It is about 1" longer.
he put said bolt in and tightened it till the nut ran out of threads and rode it...with no compensation for the added length. This caused 2 things: My swingarm has spread itself to the width of the longer bolt, and the left side bearing walked out of its position a little bit. When I put in the shims to tighten things up it forced the inner race of the right side bearing to run out instead of pulling the left side bearing back into place (no surprise there).

New bearings and seals will be here this week, and hopefully I will get this back together correctly next weekend.

And if I ever meet the PO that f@#%ed this bike up in such STUPID ways.....well, hopefully the jury will be you guys.

You really ought to stop complaining about the Previous Owner. If you didn't check the bike over properly, or get someone who could, before buying it, then it's your own fault and you have no reason to complain.

Those swing arms are heavy and really strong, I seriously doubt it expanded to take up all the space on the axle, assuming the axle really is the wrong one. A KZ1000 swing arm may bolt in, but it would be about an inch wider, so that may be the cause.

Make absolutely sure you have the correct wheel, axle, and "ALL" spacers, including the one inside the wheel. Any spacers missing will lead to self destruction of the wheel assembly.

And if you don't have a manual, get one. They are available on eBay, from the dealer, and pdf versions are available for download.

Post pics of the bike and the rear wheel and hub, it will make it a lot easier.

Yes..I have no one to truly blame but myself...just had a whole lot of different frustrations going on and this one finally got the vent!

I finally figured out what was missing!


PO lost spacer #24, so he put #4 on the right side to replace it and then moved #13 to the where #4 had been leaving an open gap between the sprocket bearing and the left wheel bearing. Because it was inside the wheel I just never realized it wasn't there, until I was putting the wheel back together and automatically put it where it was supposed to be and then couldn't find the other spacer. I tore my shop apart looking for the spacer that had been on the left side when I pulled the wheel, but couldn't find it, because it was back where it belonged!
At least my shop got cleaned up!

Anyway... the wheel is back on the bike now with everything tight and working. I'm going to get a replacement wheel soon as this one needs the spokes replaced anyway and will get the proper right side spacer at the same time.

I had put on a custom solo seat I had laying around while I attempted to make a new seat cover for the stock seat....

(rear wheel was off for new brakes and bearings)
After spending about a month on it I ended up with this!
www.facebook.com/photo.php?fbid=10202459745683572&l=6157f748b5
(sorry couldn't seem to get picture to insert?)