After almost three years I thought it was time for an update. This project for pushed aside a couple of years...

I started off with a front end rebuild. New set of fork tubes to replace the rusted originals. A forum member set me up with a nice used set. New seals, progressive springs, and tapered head bearings. Painted the lower tubes and triple tree.





New left switchgear, headlight bracket, and front master cylinder, all universal parts off eBay. You knw what the say about universal part, they fit every bike equally poorley.

Removed swinarm to paint and install new bearings. Found it to be cracked. I used a cut off wheel to open up the crack and welded it back. Its a temporary fiix. I have a gpz swingarm for a possible future wide tire conversion, but I'm considering a gs1100 so I can keep the wheel and brake stock for now if anyone has one for sale, let me know.





I cleaned up the hacked wiring harness, added turn signals, converted to blade style fuses.

Replaced JIS engine screws with stainless Allen bolts. Added engine guards. Thought I could find a cheap used set, but as common as they once were they best deal I could find was a new blemished set.

I "un-cafed" by ditching the clubman's and flipped footrest for superbike bars and stock controls.

"So Bob about your fork set up - you say you run the stock fork uppers with the 650 fork lowers?" Yes.

"I am guessing that the kz650 fork uppers must be shorter than the 900?" Don't know because I just purchased the KZ650 lowers from a junk yard separately from the uppers.

So Bob about your fork set up - you say you run the stock fork uppers with the 650 fork lowers? I am guessing that the kz650 fork uppers must be shorter than the 900? I found a set of 650 forks that look much nicer than my kz900 forks- once I took off the dirt bike style accordion fork protectors that were protecting all of the pitted chrome underneath! I haven't been able to find the total length of the two models to see if it would be worth the trouble or if I'm just opening another can of worms....

I took a last look before I put my old arm back on. Had to go into town for supplies. I didn't put the boxes on. I could feel the loss of drag in the high winds today. I'll put them back on anyway.


I was hoping to get a better shpt of the chain run. It lines up well.


Awful damn close.





Bossie without the bags/boxes.





Steve

Slowly but surely something is taking place...............ok really slowly but we now have rear wheel bearings that have the correct centres to take the ZZR1100 axle. Funnily enough the bearings are standard rear wheel bearings that I had as a spare for my KZP. Bearings had a spell next to the peas to contract a bit and in we go with the new crush tube. Job's done! We now have a rolling chasis! I won't finish fitting the rear wheel with spacers and brake caliper bracket until the engine is in so I can line the sprockets up correctly. With the rolling chasis done we can tick off new forks, clamps, front calipers, swingarm, shock, and rear wheel as fitted which means I can now pull it all to bits again and get the rims, frame, suspension parts coated/painted.

Got it on. Nice and tight, no slop. Trouble is, the bike will be lower and there is no room left on the adjuster. I'll have to spread the muffler mounts or cut off the mount eyes to lower it. I'm ordering a 98 link chain. STILL NO SPROCKET.












Looks like the new arm is about 2 1/2 " longer. I hate to cut things off and it was said I could spread the mounts. Anyone have suggestions on how to do it? I took some clips but there's a smudge on the lense. Sorry about that.
Steve

Greetings,

I too am going with the front end GSXR conversion from CognitoMoto. They offer the completely assembled hub/spoke/rim package for this conversion, guaranteed to be compatible. There stuff is definitely pricey, but I'd say its all quality. I'm going 18x2.75 to replace the stock 19" front. That's the same size rim they used on their Fox CB350 build.

I also had CognitoMoto do a new custom Sun rear rim on my stock drum brake hub (with their hub service and anodizing, installed new AB bearing & seal kit while their at it). Its a matching 18x2.75 rim; both front and rear tire diameter is 4.00x18. Remember to confirm that any new tire diameter on the rear will clear your swing arm and tail/fender/license plate or whatever you have back there. But if you're going to a new swing arm then you have lots of options. There are charts out there for recommended tire size to rim size compatibility; check the Avon Tyre website, for example.

And when purchasing stuff from CognitoMoto be certain to select all options you want i.e. additional charge/item for rim color anodizing; speaking from experience on this one :blush:

I think I know the answer to this but I'd like some suggestions. I'm ready to fit the arm to the bike. I have three bushings made of different thicknesses and some shims if needed. I'm looking at two makes of O ring chains, DID or RK. The difference in price is about $20. I figure 98 link will be enough but I won't order until I have it on and splice a short section to the chain I have now for the actual count.
Which would you buy, DID or the cheaper RK? If one is made in CHINA, it will be SHT canned.
Steve

650ed wrote: If you had a 72 mph speed wobble something is still wrong with the bike and the damper is only masking the problem. I guarantee you that the bike didn't have a speed wobble when it left the showroom floor. #1 suspect would be tires, but bad shocks; worn swing arm bushings; bad steering stem bearings; wheel bearings; untrue rim; etc. are also possibilities. I highly recommend you identify and correct the problem. My KZ650 had a wobble at 90 mph and after replacing all bearings, bushings, shocks, etc. it turned out to be a bad tire (Michelin Macadam) even though both tires looked perfect. After replacing the tires the bike is now as solid as a rock up to top speed (120 mph). Ed

Before the first wobble, all the items you mentioned had maybe 400 miles on them from new. AB bearings everywhere except the swinger which is a NOS set. I trued the wheels myself then had them OK'd by a few buddies at Trophys. Followed the directions on kz400.com to the T to rebuild and fill the forks. I pressed the new top and bottom AB races on but I didn't re-torque the stem after putting some miles on them.

BUT now I have an old (New) problem!..FFS!! Practically the exact same spot as the last, Tuesday morn on my way to work, ROD KNOCK!!.my first thought...WTF!?! Wasn't hot outside at all. Oil was slightly more than half on the window. Since the first time around, used GTX 10/40 for start up. Rode maybe 50 miles, drained refilled with another round of GTX, put about 600 miles, then switched over to RP 10/4. Put another 1k miles, then another oil change of RP. Wondering if riding the bike 15 miles with the counterwieghts 180 out on the new con. bearings had an effect? But the was about 2k miles ago? Not gonna fuck around this time, on the hunt for a crank with cons attached.

ed

azman857 wrote: I might be completely off the mark here but instead of being a breather maybe it's an oil return from the breather? Like the breather vents to a large can where the oil seperates from the vapers and returns to the crankcse.
Just a thought...

That may be. My thinking at this stage was that it was unlikely to be part of a "conventional" breather system as surely as the oil heated and was sloshed around it would make its way up the pipe.

Have been wondering if it was meant to be some kind of return for an oil cooling system.

As mentioned this came off a bike that was formally a drag machine but was really just a roller when I got it and was mostly apart, with the whole top end off. It hasn't been run since probably the early 90s. The bike had a clubfoot swingarm, super long rearset pegs, and some frame-bracing. The engine had a number of drag related mods too, like the starter motor and mechanism had been pulled, head has some porting, what looks to be an aftermarket shift drum, welded crank, etc.

I've stripped everything down, added more bracing to the frame, swapped the swinger for a Zepher 1100 unit with Works shocks, zx7 front end and mags and now I'm re-assembling.

Engine-wise, I'm going with 1075 with Wisco pistons on this guy and some slightly more aggressive cams, a set of 29mm smoothbores and I have a Yoshi 4-1 pipe from the 70s that may or may not be genuine, as I can find no marking on it at all, though if it is a copy, it's a very good one..

Here's a pic of the chassis as it stands now. (please excuse the pic - need to take some better ones).