What do I do first? Snap and stalled.

I'm about 150 miles away and have a head and some used pistons, but you would probably need rings. Or I'd swap you a set of used GPz750 pistons (they would fit right in) and new rings for a set of .020 (.5mm) oversized GPz750 rings

You need to have your cylinder bore checked before you do anything.

I don't think the bores are worth checking. I was amazed of the amount of damage. I had chunks of metal in my header pipe the size of peanuts and in the oil pan. I'm going to start looking for a Spectra top end, open the bottom end clean and rebuild it. I've come to the conclusion that, yes it's not worth much more than $1500 running but it's not about if I can get my money out of it. Besides I keep trying to think of something to replace it with and no other models really appeal to me. Seems strange considering the performance and ride short falls it has compared to other newer bikes.:silly:

Besides I keep trying to think of something to replace it with and no other models really appeal to me. Seems strange considering the performance and ride short falls it has compared to other newer bikes.

You do realize you are on KZR where we all are certifiably insane in the same manner?

Cylinder could be fine or it could be toast, no way of knowing without checking. Why a Spectre top end specifically? I think the KZ/GPz/ZR7 interchange and I assume the Spectre does also, I just don't know of any advantage to using the Spectre. KZ750 uses a mechanical tach, 83-85 GPz750 head has no provision for the tach, I don't know about the others.

You think you're crazy? Sheesh, I ride a 750 twin, although someday maybe I'll finish my GPz750

Paul Smith (smithgpz) lives in Columbus and works on the old bikes.

Well, at least I'm not the only one nuts over the look of these bikes. My brother is a Yamaha fan....I don't get it? But, he doesn't mind letting me ride beside his Vstar 1100 custom.
The Spectra because the cams have .05mm more lift and a longer duration. More lift and open longer means more air and fuel. Add that to the smaller piston diameter gives a tighter combustion chamber. These details of course are what I have read. So I can't confirm this from first hand measurements or spec comparison.

A little side note. I faught with seperating the head from the cylinder bore for a while...pulled and proded. Even tapped on it thinking it was just sealed tight from years of compression. Then realized two 12mm bolts on each side of the cam chain pass through.....RTFM. So much effort and frustration that could have been avoided with 2min's of reading!

those are called mystery bolts!:whistle: every project has them! the problem with new bikes is they look just like every other new plastic wraped bike that rolls off the line these days.i could go out and buy a new zx-14 and probably be money ahead,but the 1st time i pulled up to a light and another one that looked identical pulled up next to me id be really pissed and id have to tear it all apart and dump another truckload of money into anyway;) so like the song says:Im old enough to know better,but still too young to care!:evil: ill keep on building old stuff,if ya wanna be practical drive a volvo!:evil:

AMEN!!

try the oldkawguy website and see if you can shoehorn a 900 or 1000 block in there...could be fun...secondly i agree with the cookie cutter look of all plastic bikes...no personality at all...hope you get it worked out..

I haven't done a whole bunch of posting. I belong to one other forum for my Explorer but now I know why some of you have been here for so long. I really appreciate the encouragement! And totally agree that the plastic wrap bikes have got me guessing "Which manufacturer is that one?" Thanks again, and I will let you know when I find an engine. To those of you that are still on the road, enjoy this season and remember you could be sitting at home with a busted bike. "Make time to ride, or ride until no time is left!"

Good news! I found an engine, complete for $300 at a local salvage yard. Sound like a fair price? I know someone said $250 but wasn't sure if location may be a reason. Ohio is not the longest riding season!

$300 for a complete motor in good condition sounds like a fair price to me.
Is this from Rice Paddy?

Yup! Good'ol guys who love the old metrics.