KZ1000 engine in KZ650 frame?

I have a 1978 KZ650C that I just rebuild the top end on come to find that the timing chain is ticking alot. Instead of tearing the engine down to fix the timing chain I will just put the newly buitlt 650 engine on another 650 frame I have. I am debating on either building a 750 turbo or a stock 1000 on my 650 frame. I figure the 1000 should be easier and probably cheaper. Can anyone tell me what is involved to get the 1000 to fit my 650C. Feel free to post about the 750 turbo too like suggestions on turbos or anything. I'd love to do both but will only be able to do one over the winter.

yep
You can do it. But the first time you need to adjust the valves
you have to take the motor out to do it.

Trust me it's more hassle then it's worth.

I will have it all built and checked out before I install it. I could have the engine on the bench and put the cams in and check all the valves. it would then be good for a couple thousand miles ( one season the way we ride around here lol) . I'm not worried about the amount of time it would take to maintain it as I have lots of time to screw with stuff like this. Any information on what I need to do to install a KZ900 or KZ1000 engine into my KZ650 frame is greatly appreciated.

Thank you,
Jordan

The biggest problem would be the lightness of the frame. This is why Kawasaki strengthened the frame all the time. Even the 77 KZ1000 engine was too powerful for the 76 900 frame
In 78 the tubes were enlarged by 1/4" on the D model for this reason and even that was not enough. The reciprocating mass on the thousand is just way too much for that frame. Also, if you rebuild the entire top end, you should re-shim the cams after the valves seat. The cam clearances get too tight. This takes about 500mi. I ride that in about seven days. Would your bike be a novelty? Yes. Would it be ride able in an aggressive manor? No. I guess that would defeat the whole purpose of putting a 1000 engine in a 650 frame.

Otto Kudrna

I'll chime in on this one as I had pondered stuffing a big litre motor into a middleweight's frame. I still may do this one day.

Your best bet is to pick up a tired 1984 Gpz750 engine, cylinders and head and put it onto your 650's bottom end. You might need to put in a new beefier clutch to handle the extra power. This Gpz engine was rated around 87 hp when new which is a significant step up from the 650's 64 hp. Get your hands on a Wiseco 810 kit, clean up the head and get a set of good carbs and ignition and you should be in the right power range of a stock Kz1000 which was around the mid 90's if I recall.

Shoehorning the engine into the frame and gussetting it to handle the oversized motor is doable but as mentioned earlier, any time you have to check valves or pull the valve cover to get to a little leak this will turn into a major project.

Steell has a 650 that has a 1000 motor stuffed into the frame that had previously been put into it by another kzr member (sbjones) and if you need to see some close up pics perhaps they can help out if you ask real nice.

Cheers-Colin Firth-Ontario Canada

reborn650 wrote:

Steell has a 650 that has a 1000 motor stuffed into the frame that had previously been put into it by another kzr member (sbjones) and if you need to see some close up pics perhaps they can help out if you ask real nice.

Cheers-Colin Firth-Ontario Canada

Not yet

The 650 has a 750 bottom end bolted in it at the moment, the 1000 (81 KZ1000 CSR) donor is still sitting in Omaha awaiting transportation to here.

Do have a Wiseco 1105 kit, 1100 cylinder block, and GPz1100 cams waiting for it.

So if a 1000 has to much power for the 650 frame, then I guess the 1105 ought to have way to much power (too much is not enough)

The frame will be seriously reinforced prior to installation of the motor, and it has GSXR suspension front and rear which lessons the weight and should help.

It's certainly not going to be a daily driver

The above bike is GPzInfested's (my Nephew and partner in crime, who also owns the GPz750 Turbo, and the GPz750 motored 79 KZ650 SR with GPz750 suspension) I'm building a 810 KZ750E with GSX suspension and fuel injection for myself. I prefer something I can enjoy riding, not something that will yank my eyeballs out of their sockets every time I twist the throttle. :woohoo:

Guess that means I am getting old (and maybe wiser)

Post edited by: steell, at: 2007/10/27 13:13

A member on the old Kzrider board- might still be archived there- stuffed, I believe, a Gpz 1100 motor into the 659 frame, and it fit quite nice- he canted the motor forward a bit to make motor in frame valve adjustments possible. It was one radical looking bike!

CruisingRam wrote:

A member on the old Kzrider board- might still be archived there- stuffed, I believe, a Gpz 1100 motor into the 659 frame, and it fit quite nice- he canted the motor forward a bit to make motor in frame valve adjustments possible. It was one radical looking bike!

Messenger1

Messenger1 part 2

One of my favorite builds ever.

Don't forget these two:




The Red one had a good write up in the archives I believe on the mods done to fit the motor.
The blue, Z Power, had a web site on the build, but it seems to be gone.

STREETFIGHTER Kawasaki z650 Gpz1170 on ebay UK.

Other side:
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