You need to use the axle that fits the swingarm, and fit everything else to that. Likely that means custom spacers and different bearings.

hello
Whell the 909 3nigne I purchased and had issues with cultch basket was making a lot of noise so I opened the engine then decided to undercut the transmission and put a billet clutch basket and MRE single stage lock up clutch.
the crackshaft had a windage tray that I left there. .
the top end was done the pistons were skirting so I bored to 1260 was at 1200, the head was ported and had a 390 and 400 cam over bucket so.
I had another 1400 engine on the side that had ported head with those valves with happen to be Manley and actually are not damaged in fact were made like that for a while to reduce contact with the valve guides, I was told by the guy at pitstop performance.
that other head with came from a 1979 LTD had CM Z6 with 450 lift and titanium springs and under bucket shims thats the reason I am using that head. its going to be a biiy detuned by a fraction.
I intend to use it sparingly on the street and eventually might go to the track on the week-end.
The frame has extended swing arm with a 200 tire and Yamaha R1 front end its a frame up build that I have been working on, since the bike that had the 1400 engine I put a brand new stock engine1015 with only a 4 to 1 dyna ignition jetted carbs and pods.
but after I had that 1400 the 1015 feels like a turtle so I want to have back another blasting fast kz.

I am fond of aluminum Kawasaki swingarms with eccentric drive chain tensioners. For one thing they are light but strong and excellently withstand lateral and twisting loads. For another thing they are stylish: no axle head or nut protruding from their sides, neither tension bolts stick out from arms ends. And in addition eccentric adjusters are helluva practical: you tight axle nut only once when install it and the process of chain adjusting becomes simple and fast thing, moreover with no need to check marks every time.

The particular feature of eccentric adjusters is rotation of brake caliper bracket around axle when axle nut is tightened. For this purpose it usually has collar and bushing: a collar became static part once axle nut is tightened and bushing, being not mandatory part, however helps bracket to rotate around collar.

This time using of swingarm with eccentric chain adjusters made things a bit more complicated, as Honda CBX550 rear wheel is designed for swingarms with linear adjusters And what is most significant, in case of CBX550 wheel the very brake shield works as brake caliper bracket, thus it couldn’t be replaced with any other bracket.



Thus, first task was to modify brake shield to make it rotatable after axle nut is fixed. Luckily, brake shield central part has body enough to machine it for collar. Bushing is not necessary part of this system, zinc anodized steel and aluminum will do, thus I made measurements, produced blueprints and ordered these works from local machine workshop.

And here is result, the collar:



Machined shield:



And that’s how it meant to work:



Next question was how to connect brake shield and swingarm with brake torque rod. The idea of adapter was quite obvious, but there was more than one way to make it. The simplest solution was to cut it from thick aluminum plate, then make holes for collar, torque rod and threaded hole for “fixer” that connect adapter and brake shield. However, I chose more complicated but more interesting way. First, I made simple PVC model to work out final dimensions and design of parts.



After that I made blueprints and give them to one friend of mine of whom I also wrote earlier: he make 3D models of parts for company that produce light aircrafts. He made 3D model of brake adapter for me:





I gave this model and plate of 30mm aluminum to guys with CNC machines and get from them ready part:



I designed it to be compatible with OEM Kawasaki Zephyr 550 brake bracket bushing. I bought new bushing, but for now I used one I had at hand in my garage, keeping new unpacked until final assembling.



I sandpapered brake adapter and made some final grinding to fit adapter and CBX550 brake shield as tight and close as possible.









I used modified original Zephyr 550 brake bracket collar and I designed and ordered all other collars I needed for rear wheel setup.



Brake adapter and brake shield with collars:





And that’s how it all looks when assembled together in swingarm:

zed1015 wrote: The chain has been running slack on the frame for quite a long time to cut through like that and it coming off has finished the job.
The tubing is 1/8" thick so you wouldn't get damage like that with a one time incident.
It hasn't really weakened the frame though and it's an easy fix by just welding a patch over it to close the holes.
2.2 to 1 is the stock final drive ratio and either 15/33 or 15/35 was the sprocket sizes used depending on model.
Sprocket sizes do nothing to affect chain tension and all that bigger one will do is bring the chain further away from the swingarm but closer to the frame rail.
Just use the same gearing you have if you are happy with it and pay close attention to chain adjustment and maintainence to avoid this happening again.

Thank you for the comment and advice, Zed! Duly noted on the the bigger sprockets and how it positions differently, but does not affect the tension.

I haven't owned anything but Harleys, so I do not have a preference when it comes to gearing yet, so as you folks suggested I am going to stick with the stock setup for now and get a feel for the "original" setup.

As far as the frame damage/repair goes, thank you guys for noting the chain had been riding on the frame like that for a while. I didn't notice that until just now - there's set of previous grooves besides the new ones that opened up. As far as repairs, my brother in law who owned a welding shop for 20+ yrs said it should really be a problem - clean it up, fill in the damaged portion, and put a patch/semi-sleeve over it (all TIG welded, of course).

Thank you all so much - haven't been this stoked on a purchase since my Trans Am (High School)!

Any other things/problem areas to advise the shop I take it to - ie: typical problematic issues with the KZs? Really hoping to ride this when I get home, and then add some things while I'm home for 2 weeks (Emgo headlight cowl, maybe 4 into 1 exhaust, etc.??).

No I don’t have a photo of it, the bike is in Canada, I am at work now. I will take some next time I am home. The wheel came with a GS 1000 swing arm and shocks. It looks weird with the spacer welded in but I am sure it will work with the sprocket and disc on there. I will mock it up and send a picture next chance I get. Thanks

Yes, threw me off when I got it, but it was on a KZ with a GS 1000 swing arm. I bought both.
Just need to figure out brakes, on the front. The bolt pattern is different on my spoke wheels, so I am guessing from an earlier bike?

I would definitely recheck things like valve clearance and carburetor synchronization to rule them out.
I would then carefully scrutinize motor mounts to be sure they are properly tightened, and swingarm bearings or bushings for looseness, and wheel bearings and shock absorbers. Is the cush drive in good shape?

How many miles on the drive chain? Any stiff sections in it?

I used a 1991 GSXR swingarm and had to notch the frame where it meets the chain to clear for a 5/8 inch offset sprocket. 180 Tire

Thanks Ed.
Ordered some soda blast media today. Will get the sand out on the weekend for the swingarm and frame fittings, then the glass beads for the fork tubes, engine covers and steering head. After that the soda should be there and I can get the block done.

So I have been busy stripping down my 1980 KZ750H so I can get the frame off to be sandblasted and get onto the rest of the parts myself (among other things). Today I took the swingarm off and was met with a pretty ugly sight. The tube that crosses underneath the swingarm pivot (has the main stand attachment and the back bottom left engine mount on it) looks like it has been beaten away at. It almost looks like the middle section was caved in to give enough clearance for the back of the oil pan - which would mean that something maybe bent.
How much clearance is there normally between this tube and the oil pan? Has anybody seen this sort of craziness before and could maybe enlighten me to how it could happen without the use of a hammer?