KZ550 powered YZ125 project

Thanks, I wanted to find a kz650 because i really like kick start engines but, the 550 was such a good deal at the time i couldn't pass it up. My friends have named this project "dirty birdie" :laugh: ....i dont know why but, i told him if he wanted to get a decal made i'd put it on the bike

I'm at work, so I can't see the pics. I can't wait til I get home to see this thing!

If you were in chicago, I'd trade you wiring your project for some welding. Nice tig avatar, by the way.

The KZ550 can be made to run without a battery if you don't mind push starting (which is what I do on my red gpz). It's actually real easy in third gear, if you can get it into third. KZ's have a positive neutral finder so it only shifts into 1st or neutral when it's not moving (just FYI), but if you play around with the shifter and rock the bike back and forth you can usually get it into 2nd sooner or later. From there, you can shift up through all the rest of the gears.

If I can't get out of 1st, I just run and jump on it to start it.

Thanks, i was finishing my down pipe for my turbo 240sx project. I dont have a tig welder myself even though i can tig weld. I usually know somebody who has one that'll let me use it.

Good info on the positive neutral finder...

That bike is looking wild!

What year 240?
You turboed the KA24 motor, or dropped in a SR20? Seems RB25 is what the hipsters are doing these days.

I just finished replacing the front suspension on my S13. If the motor blows up soon, I may look into a swap. 200K and still going.

Awesome work on the frame! The bike looks excellent! Doesn't look like so many projects of this nature - thrown together and a total disaster. This one looks super professional.

You might be able to get info on hillclimb bikes if you still need any details. I've seen several KZ-powered bikes in that sport.

Just happened to think - the only thing that would have made it better is if it were a KX. Still very cool even if it is kind of a Yamaha. :laugh:

79MKII wrote:

Awesome work on the frame! The bike looks excellent! Doesn't look like so many projects of this nature - thrown together and a total disaster. This one looks super professional.

You might be able to get info on hillclimb bikes if you still need any details. I've seen several KZ-powered bikes in that sport.

Just happened to think - the only thing that would have made it better is if it were a KX. Still very cool even if it is kind of a Yamaha. :laugh:

Thanks for the kind words. You know those yamaha's need some help in the engine department....if it was a kx it would still be running

loudhvx wrote:

That bike is looking wild!

What year 240?
You turboed the KA24 motor, or dropped in a SR20? Seems RB25 is what the hipsters are doing these days.

I just finished replacing the front suspension on my S13. If the motor blows up soon, I may look into a swap. 200K and still going.

89 240sx fastback....I boosted the KA24E single cam bad boy. H1C turbo off a cummins diesel and 1000cc injectors running on e85. I love that corn fuel. If i can find the right jets and needles i might switch the kyz550 to e85 also :blink:

79MKII wrote:

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Just happened to think - the only thing that would have made it better is if it were a KX. Still very cool even if it is kind of a Yamaha. :laugh:

Thanks for the kind words. You know those yamaha's need some help in the engine department....if it was a kx it would still be running

[/b][/quote]

I like your thinking! Very good point! :laugh:

Yeah, my buddy who tune's turbo Saabs keeps trying to get me on E85. Might have to look into it

Sweet lookin' 240!

kinda late now but, the coils i have measured out to 2.5 ohms and from what i have read i'm not sure if that will be ok. After a quick google search i found my orginal source of info (before i bought the coils) where the poster said his stock kz coils measured out to 2.7ohms but, after looking through the manual i read for a points ignition you should have 4ohm coils and a tranistor ignition 1.5 ohms. Are my 2.5 ohm vulcan coils too hot? If so could i put a small inline resistor to raise the primary resistance?

p.s.

I made my new rear brake pedal and started to trim up the drive sprocket cover so it will fit. Any one know where i could get the cheapest set of exhaust collars or can you make them out of this wall pipe cut to length?

nelson8708 wrote:

kinda late now but, the coils i have measured out to 2.5 ohms and from what i have read i'm not sure if that will be ok. After a quick google search i found my orginal source of info (before i bought the coils) where the poster said his stock kz coils measured out to 2.7ohms but, after looking through the manual i read for a points ignition you should have 4ohm coils and a tranistor ignition 1.5 ohms. Are my 2.5 ohm vulcan coils too hot? If so could i put a small inline resistor to raise the primary resistance??

The manual is wrong. The kz550 coils for Kaw electronic ignitions were all 2.4 to 2.7 ohms. The '82 550's came with Kaw electronic ignitions, not points. I believe only the 1980 KZ550A had points.


nelson8708 wrote:

p.s.

I made my new rear brake pedal and started to trim up the drive sprocket cover so it will fit. Any one know where i could get the cheapest set of exhaust collars or can you make them out of this wall pipe cut to length?

The Mac 4-into-1 systems for KZ 550's don't use the half collars or removable clamps. They just welded a sleeve over the ends of the tubes and had the clamps permanently stuck on the pipes. You could do the same thing. Just make sure the overall outer diameter of the header pipes doesn't exceed the diameter of the recess in the head.

Or you can jsut wait it out on ebay. The half collars and clamps come up pretty often.

Also, make sure ther are no old copper crush rings still stuck to the head. That is very common. You should only use new ones each time you install the headers.

No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationThe price on this is not too bad. You don't need these if you use a Mac exhaust header.



The picture only shows 4 of these half-collars. He doesn't say how many he has, but you need 8 of them (none if you use a Mac).

yeah, i saw those on ebay. For clearance issues i am going to use a stock header but, will probably end up modifying it. Thanks for the good news on the coil resistance. I noticed today when i removed the ign cover that there were no points. I also reset the timing chain like you suggested. That is another good idea with just welding some tabs onto the stock header to hold it on. Will probably do that since it will be the easiest way and save me probably 20$. I still need to get part of the head welded where an exhaust stud was broke off. When the bike was dropped it took the stud and the protruding aluminum part that the stud threads into. I feel like i am getting closer to the finish line. I will be ordering new fork seals this week so i can start on the fork rebuild. After that its a matter of getting front and rear sprockets (17/44), a longer chain, making a throttle cable bracket and finishing the tank.

Anyone ever run a 530 chain on a 520 sprocket? The yz rear sprocket is a 520 and the kz sprocket is 530. I put the 530 chain over the rear sprocket and didn't for see any issues but, the calibrated eye isn't always right if ya know what i mean :laugh:....