GPz750 motor questions.

I've just got a GPz750 motor to stuff in my KZ650B1 this winter & was curious about a few things.

Can someone decode the number for me? I want to make sure I don't have the weak '82 only version. KZ750EE111486

Does this have five or six gears? The cover is missing that would have the shift pattern on it & I've seen places that claims they have five gears, I thought they had six!

Where the CDI goes is a bit busted up, two dime size chunks gone. How would I got about having this fixed?

Man I'm stoked to get this thing in my baby! Thanks for any help you can provide!

Hey freak look at the front of the head the 82 would have a tach drive just above the #2 cylinder. If its later then this area should be filled from the factory. I don't remeber how many gears either. If yo can't find a real answer then let me know and I'll dig out my cover and look.

Recently had a 750 was five speed 550 was six

Five speed for sure for the 750. No tach drive of these heads. Sorry I can't decode the motor number for you.

Another option for you if you run into harness or other issues is using a Zephyr Harness and CDI. They are "almost" exactly the same.

When I converted mine with the ZR motor was intending to use the Zephyr CDI but the one I picked with the used harness was bad. So converting to Dyana 2000 was the next logical conclusion.

This allows you to do static timing and an over all upgrade/refresh of your ignition system.

Thanks for all the replies guys! I never thought about looking for a mechanical tach drive on the motor, duh!

By freak chance, could I put a GPz550 6 speed in this motor to make it closer ratio?

I plan on putting the 650's electrics on the motor since they're already there & work great. Thanks again guys!

Placing the 550 gpz transmission in the 750 case has been done. Not by me though. Kick myself for letting an 82 550gpz slip through my fingers several years ago. The transmission was about the only thing I could use other than the bars that I needed off of it.

I'm not seeing any advantage to using the entire GPz motor if I'm not gaining a gear & wanting to keep the factory look intact as much as possible, I think I'm going to just put the oil pan, jugs, head & pistons from the GPz motor on my B1's cases.

This for me would solve a lot of little problems. I wouldn't have to have the GPz's case fixed where it's busted up around the iggy cover. I'm wanting to use the original b1's electrics & since the chain cover to the GPz motor is gone, this would solve having to track down more parts.

From what I've read, all that would need to be done is have the B1's cases bored out to accept the GPz's sleeves & switch the cam chain sprockets out.

Anything I'm missing here?

Franken motor it is...

I'd be supprised of you can use the oil pan. You may end up with a problem with oil starvation... Somone else may chime in as I'm nt sure what a 650 pan looks like.

Going to the top end I beleive this is correct. Although you may have to go with external oil lines to the top as the galley through the cylinder may not work any longer.

kawasakifreak77 wrote:

I've just got a GPz750 motor to stuff in my KZ650B1 this winter & was curious about a few things.

Can someone decode the number for me? I want to make sure I don't have the weak '82 only version. KZ750EE111486

Although you probably have figured it out by now, and the motor is painted entirely black, you most likely have one from a ZX750-A1...the 1983 year model GPz. The motor VIN series that went into this bike started with KZ750EE110001...

Thanks mcdroid, I had now idear about the engine series.

kzr750r1, the oilpan is a direct swap, it's a very popular mod to add an oil cooler to the 650's. A friend has a B1 motor torn down so I can use it for reference when it comes to oil galleries, etc.

I tore the top end off last night & it looks pretty good. My digi batteries are dead but as soon as I can, I'll post pics for ya'll.

Did you get the information you need for the CDI? Personally I'd just go with a Dyana and forgo the pain of finding a working OEM replacement for working new parts.

Thanks for the information on the pan. Good to know.

I wish you luck on the mod. Your probably lucky with the later Gpz but as I understand the lower end (case)were updated from the 82 to 83. Kind of the main reason I've moved to the ZR motor for the bottom end updates.

One of these days I may try a ZR7S motor in mine.

Looking forward to the pictures.

My plan the whole time has been to reuse the dyna.

I won't start tearing into my B1 until something serious breaks, there's snow on the ground or I find a reliable replacement (after my vacation, I've got a lead on a nice KZ750 for chump change).

But yes, this will be a well documented conversion, if it's possible that is.