What is my engine??

Hi eveyone, im new here.

I have just bought a project bike, its a z650 with a 750 engine, i think.

The engine No. is kz750ee030548 as stamped on the crank case. So i started to take it appart to do a bit of a rebuild and possibly a re-bore 810cc.

Took off the cam cover but it has a standard chain not a hi-vo?? Hmm, ok, so i took the head off and measured the bore size, 62mm Hmm again?

The stamping on the engine looks factory. Is it possible somone could of put 650 barrels, pistons and head on it? How can i tell? do the barrel sleves have lips on cus it looks like there is alot of barrel still to go at for a rebore?

Any help would be fantastic, many thanks, Jim

Hello Jim...I think you have it figured out...someone has dropped a set of 650 jugs onto a a 750(4) lower/tranny...and it appears that they used an old-style 650 too. Usually people drop 750 jugs onto 650 motors...so, in essence, you still have a 650 with a 650 motor.:whistle:

Welcome to the site Jim. 650 is still cool in my book. :whistle:

Best of success.

Bore x stroke: 62.0 x 54.0 mm (2.4 x 2.1 inches) is a 650cc, 66.0 x 54.0 mm (2.6 x 2.1 inches) is a 750cc, and 78.0 x 78.0 mm (3.1 x 3.1 inches) is a twin 750cc.

If you have it already apart, you can make that 650 a 700cc. with the Wiseco W-K700 kit:
www.pro-flo.com/pro-flo_wiseco_kawasaki_big_bore_kits.htm

i think all the 750's had a hy-vo timing chain. someone would have to had went in and put the crank of the 650 into the 750 block to run a regular timing chain. i would just measure the bores as other have descibed to determine you engine size.

Thanks guys, you confirmed my suspicions. So it would definately have to be a 650 crank to run the chain?

If i wanted it to be 750/810 again what would i need to do?

Can i use the wiseco 810 pistons etc on the 650 crank/conrods if i get some 750 barrels and bore them out?

What about the cam chain, can i keep the standard chain or do i need to convert back to hi-vo?

Mcdroid-(and it appears that they used an old-style 650 too.) What makes you say this?

Thanks again

Jim

Jimbo750 wrote:

Mcdroid-(and it appears that they used an old-style 650 too.) What makes you say this?

Thanks again

Jim

Jim, I may have misspoken...I went back and checked and it appears that all the 650's (including newer models 1981/2) had the simple cam chain while the 750's had the hy-vo cam chain...suggesting that you have the 650 crank in your bike:)

Go to the parts diagrams at kawasaki.com and look up the part number for a 1980-83 KZ750 cam sprocket, then copy and pasted it into the part number field of the Parts page.

You will discover that the 81-83 KZ650 CSR uses the same cam sprocket, and that means the 81-83 KZ650 CSR uses a HyVo cam chain.

If you look up the 1981 KZ750 cam chain part number (92057-1319) and do the same thing on the parts page, you will find that it is listed as being used on the 81-83 KZ650 CSR also.
The 81-83 KZ650 CSR is the only 650 listed as using the HyVo cam chain, and it's also the only KZ650 shown for 1981-1983.

The 1980 750 cylinder block and head have provision for the roller style cam chain, both were changed for 81, although you may be able to get them machined to work (Reborn650 was checking into that).

I don't yet have reliable info on whether or not the 650 sleeves are thick enough to be bored out for the 810 kit. They appear to be thick enough just looking at them, but as far as I know, no one has done it yet (and I don't have a 650 cylinder block to pull a sleeve from).

Post edited by: steell, at: 2007/10/28 22:24

Thank you Steell...I should have looked at the part numbers, but choose to look at the KHI shop manual where it shows the cam chain (in an exploded diagram) for the KZ650H series as being a simple chain, in contrast to the part numbers, which make it a hy-vo. So I stand by my original statement:)

Mcdroid wrote:

Thank you Steell...I should have looked at the part numbers, but choose to look at the KHI shop manual where it shows the cam chain (in an exploded diagram) for the KZ650H series as being a simple chain, in contrast to the part numbers, which make it a hy-vo. So I stand by my original statement:)

The parts diagrams have been found to be incorrect sometimes as well, but at one time I was contemplating installing a 750 top end on a 650 so I did lot's of research. And during this period I found other info that supported the parts diagrams this time, so I'm reasonably sure the parts diagrams are correct on this one.

Colin (Reborn650) is looking into installing a GPz750 head on his 810 kitted 650, and it appears that the head can be modified to work with the roller chain at nominal cost. But I don't know if he has done it yet.
I have enough 750 motors, so I'm no longer concerned about installing 750 cylinder blocks on 650's


The original poster identified his bike as a "Z650" which is a designation not used in the US, and the Kawasaki parts diagrams are North American (US and Canada) specific, so none of this info may even apply if it is a non North American model

Post edited by: steell, at: 2007/10/29 08:57

How can i tell if it is a 650 head or a 750 head. Is there much differances, valve sizes etc?

I have a set of 750 barrels on the way and am trying to figure out what else i may need to get.

Much appreciated, thanks Jim

p.s. it is a europeon model

750 head has bigger valves, ports, and combustion chambers, and the only 750 head (North American models anyway) that will bolt on with no machining required, is a 1980 KZ750 head.
At least as far as I have been able to discover (the 81 and newer head has a different part number).

The 650 head will work on the 750 cylinder block, that's what Reborn650 is using.