Skidmark wrote: I would verify your tach first.

First thing I did this morning and it answered a load of questions! It always felt like idling at 1500 rpm was the sweet spot, it just didn't seem to idle well below that. Hooked up the digital tach today and look at that, 1500 rpm is more like 1150-1200! Still a bit higher that the manual, but an idle speed of 1100-1200 instead of 1000-1100 is fine, whereas 1500 was really bothering me.
After that, I resynced at the new idle speed. Still a bit of variance on the sync gauges when revving, but nothing major. I let her cool down, then retorqued the cylinder head nuts. I also cleaned the plugs as I'm not doing anything more until after I've put a few hundred mile on her.

Final bit of work was the overflow tubes for the carbs. They go to the air box and I routed the airbox drain tube down the swing arm so anything that comes out should miss the rear tire, exhaust and brake disc.
All done now. Ready to get an MOT as soon as the license plate bracket arrives. Will give her a dust down and wax the tank this week, then I'll take a few more photos.

hi all tanks for letting me join. I have a burnt out special I found online. The previous owner seems to lost key for it. Hacked ignition switch and caught bike on fire of course I could not tell until sale was finished as it was an auction.... At least I got bike for 150 plus tax. Like 225 out the door. I still need to find controls and levers and brake cylinder. Right now I need help with the correct tool to pull the swing arm bearings. There is no play and I did not plan on replacing them. However the paint is soo fucked in many places. I was going to send frame out for paint however they seem to want the bearings removed. Please advise on what is the proper tool to remove the swing arm bearings. Also can they old ones be put back in? I don't normally do that with any bearings. However this project bike has turned into a bit of a nightmare with replacement of all electrical components. I have already bought the motion pro swing arm bearing removal tool but it does not seem to fit as the tube the is solid instead of only having the spots where the bearing rides. Thanks for the help.

So I did also take a good look at the passenger footpegs from behind, and the left side appears to be askew (not square) relative to the frame of the bike. I can try to get a shot of it at some point.

However, based on another forum user's confirmation of my measurements of the distance between the swing arm and footpeg mounts with his bike, I'm thinking that this is the way the motorcycle is, and that the frame is NOT bent. That would mean the problems I am experiencing are due to part incompatibility

I was able to obtain a part number for at least one of the mufflers based on a picture in the ebay listing, 18001-1126, which I think was for the right muffler based on the picture. It ultimately means nothing though, because this particular part number is not listed anywhere that I have seen. I'm not too concerned though, as the part numbers differ between fiches, as we've already seen. So its all inconclusive as far as I'm concerned.

So here are my thoughts. I have my original pipes with a rotted out crossover and mufflers. I have a brand new set of kz stock pipes, one of which fits, the other that almost fits, both of which I probably can't return at this point. As far as I can determine, the fitment problem is related to how far the muffler mount extends towards the center plane of the bike. Instead of attempting to bend the frame (which I don't even really know that I can do without major hassle and weakening of the frame), I can shave a 1/4" of metal from the inside of the mount in an attempt to give the muffler more clearance . Based on what I can observe, I think it will do a lot of good. I can also attempt to make adjustments to the angle of the mounting bracket on the muffler. I think with a bit of work, there's a good possibility I can get this muffler to fit. If not, I can install washers as spacers and reinstall my old mufflers, and continue to put along at sub-highway speeds. As far as I can tell, those are my only two options, so I might as well attempt!

Eakin wrote: I'm still collecting parts for my EFI build, but have been thinking a lot about keeping my Dyna ignition and using the tach signal to trigger the MS, or if I should retrofit a trigger wheel in there. I'd love to see where you end up with this.

I'm also building a MS setup in my old Volvo 240, but luckily that's a pretty well documented process. Yoshifab sells a CAS adapter that they've retrofit in to a distributor housing to simplify installation. Their trigger wheel is pretty small, and available separately. Do you think something like this might work for our bikes? I'd have to get another sensor and fab a mount for it, but that all seems manageable. Would save getting a wheel cut.

yoshifab.com/store/high-resolution-dsm-cas-trigger-disk.html

I believe the megasquirt has a dual trigger mode that may work better with the stock ignition.... yep here it is on the megasquirt docs , its called dualspark meant for vtwins etc.

As for that trigger, yes it could work. The wheel needs to be 67mm (offset 8mm out from the crank end which puts it out past the TDC mark but in between the three posts that mount the stock trigger plate) or 58mm (mounted flush to the crank end and is approx same diameter and location as the stock advancer).

Going above the stock trigger plate could work if the sensor is mounted first, and then the crank trigger is installed over it (sensor would point out). Lots of ways to do it. Im trying to stick with VR as thats what my ECU is currently setup for.

Kawasakik1e wrote: Ok, very cool.what your doing there Saablord......! I'm extremely busy with those home improvements I mentioned.
Really wanting to start 1st stage of getting motor running on the MS2 but it will be a bit before I start on that.
You said you might need a frame? I have a 81 kz750 frame, no title... I'm taking the mags and swing arm. Forks are junk. I'm In WI. If you want the frame, I'll give it to you.... it would be best to blast and powder coat it. You pay shipping, it's yours.
Email me at 2000zrex@gmail.com of interested.
Everyone else following this thread, glad to have you aboard!

Life always gets in the way! But, i'm not sure where i want to put this motor yet, so ill pass for now.

z1kzonly wrote: Cool! You lost me at 1st sentence! But you made the Honor Role in class! I remember Hillborn Injectors running Methanol on 3/4 midgets and dwarf cars when they still used air cooled Z engines!
Very nice work! I am sure that the line of work you are in, gave you this knowledge!

thanks, Hah! I guess i did! Don't really think about that anymore... I'm just a guy with too much time and money on my hands with a fab shop at work!

Here's where im at with the crank trigger...

Test fitting the 3d printed crank trigger wheel to verify my TDC offset. Im using the stock advancer base as a mount for my wheel. Now that i have an accurate model of the TDC offset, i could get rid of it for a completely custom mount. But it's also nice keeping the 17mm crank nut.


Model of the new bracket (white), trigger (blue), and existing mounting locations (transparent)


I'm hoping the wheel is large enough for the sensor to properly detect the teeth and gaps of the wheel... If not ill have to reduce the teeth down to 24 (currently a 36 tooth)

Magnetizing the sensor will also be a challenge. I plan on throwing a 25mm neodymium magnet on the mount plate and see what it does!

Edit: test fit of the brackets

Ok, very cool.what your doing there Saablord......! I'm extremely busy with those home improvements I mentioned.
Really wanting to start 1st stage of getting motor running on the MS2 but it will be a bit before I start on that.
You said you might need a frame? I have a 81 kz750 frame, no title... I'm taking the mags and swing arm. Forks are junk. I'm In WI. If you want the frame, I'll give it to you.... it would be best to blast and powder coat it. You pay shipping, it's yours.
Email me at 2000zrex@gmail.com of interested.
Everyone else following this thread, glad to have you aboard!

So I took another really good look at the mufflers and found no visible differences. I found that I can get the left muffler into place with few good thuds, but it sits on the swing arm (pictures 1 and 2). So obviously that won't fly.

I like the suggestion of looking at the footpegs from behind to get a sense of whether the frame mounts are bent. The mounts differ in their distance from the swing arm on either side (pictures 3 and 4, left and right sides). The left side frame mount sits about a 1/4 inch closer to the swing arm than the other side.

Maybe bending the frame mount outwards is the solution after all? If so, it seems like the only way to do will involve taking off the belt so I can torch the frame and use a pry on it. My ears are open to any other suggestions.

Usually rear brake caliper’ torque rod is strictly utilitarian looking thing. To make it of steel was also the simplest option, especially taking into account the fact that there is a 6mm offset between torque rod mount on swingarm and brake caliper holder. So KZ650 project might have quite ordinary brake torque rod if I wasn’t working on it simultaneously with working on the chain guard.

Idea of torque rode as some kind of “counterpart” to chain guard was pretty obvious to me. First were measurements.



They were closely followed by pencil sketch. I used to do such sketches (or simpler ones) beforehand to drawings that I make on computer.








That’s what I’ve got as an output:
Then I produced 3D drawings and brought them to CNC shop along with plate of 2024 aircraft grade aluminum.

From previous part of story about chain guard attentive reader (or rather attentive picture looker) might notice that chain guard inner mount was already attached to new mount bracket. This mount is longer than original and placed farther from swingarm axle. The reason of such modification is that Kawasaki KZ650 sprockets lay in plane that close to longitudinal axis of motorcycle than plane of Zephyr 550 sprockets. Let me demonstrate this by placing a strip of paper tape on Zephyr 550 swingarm:



This strip of paper tape has width that is slightly larger than width of trace which 525 chain leaves on rubber chain slider, and its position is verified by laser tool. So we may say that it marks optimal position of chain slider for KZ650.



Now let’s put original Zephyr 550 chain guard (used, so we clearly could see the trace of Zephyr 550 drive chain) on the swingarm. And as we could clearly see, potential KZ650 chain’ trace is shifted to right (or to center of swingarm) comparing to trace of 550 drive chain.





On practice it means two things:

• Zephyr 550 chain slider does not cover all operating width of KZ650 chain. It’s likely wouldn’t be an issue, as long as drive chain is properly tightened. However it’s slightly inaccurate, so I will think about possible solutions for this issue;
• KZ650′ chain would be too close to inner mount of chain guard.

Hi all,
I am planning to replace the rear suspension unit on my GPZ 750 Unitrak model by a Wilbers or alike.
At this opportunity I would also like to examine, grease and, if needed, renew the various needle bearings constituting the Unitrak system.

While for the most UT components and levers it is pretty obvious on how to dismantle them, I am though not sure how to dismount the 22mm wrench size bolt that connects the rockerarm to the frame.
I dont seem to have an idea on how to pull this darn 10-15 cm long bolt as the centre stand gets in this way.
There is only around 10mm room to maneuvre. by far not sufficient to pull off the bolt. See picture.

One may think to just fold up or remove the centre stand which would sure provide enough clearance but since the rear wheel has to be removed first before disjointing the suspension I need the centre stand folded down to keep the machine standing upright. Hmm, bit of a drama ...
In a professional workshop they may have other supports availiable to keep the machine in a firm position but in my humble garage I dont.

Now I ve been pondering hard on a plan on how to overcome the issue before I'd start the work.

Here is my point:
I was wondering if anyone has ever dismantled the Unitrak swing arm and suspension system including the rocker arm and may have a hint. May be there is a trick I dont see?

Ideas appreciated

Thx in advance !!!!

If those shims aren't noted in the parts diagram I could only assume someone put them in there to tighten things up a bit. It could be the end caps or other parts were worn and the previous owner didn't want to replace them. Are end caps on the sides of the swingarm? I am just guessing because I am not familiar with this bike. In any event it certainly doesn't sound right, but I am sure others will chime in. Do you have a service manual for the bike? I would be surprised if this was some sort of suggested repair to tighten the swing arm up but one never knows. It couldn't have been very easy forcing the shims in place.
Rick H.