What year is this engine?

On my day off (Monday) I went to pick up another bike that I bought off Ebay. This guy had tons of stuff he wanted to sell but much of it was junk. I was thinking about picking up another spare 550 engine but the one he had was stuck. While we we digging I came across a GPZ 750 motor. Looked good and turned over fine seemed to have good compression. After a bit of wheelin and dealin I loaded it up and went away happy, having bought it for $75.00 I'm thinking I'm gonna use it in my 79 650 B with some VM 26 carbs I have and run an RC Engineering header. The guy said the engine was an 83 but the Kaw website lists an 83 as being a Ninja. The engine # is KZ750EE 146028 can anyone here tell me what year bike this engine is from. Thanks in advance.

Zedder only lists KZ750s thru 1982, and the engine numbers stop at 078049.
Seems like yours is an engine for a KZ750 that was made after 1982. I'd heard that Kaw produced engines after the production run of bikes, to be used as spares. Maybe that's where your motor came from?

Here's the link to zedder:

zedder.com/msg1.htm

Kawasaki produced 750's for North America through 1985 (using the KZ750EE motor) These motors (in 1983) went into both KZ750 frames and ZX750 frames and into only ZX750 frames in 1984. Neither Zedder.com nor buykawasaki.com list engine numbers for for the ZX750 series. Be also advised that Kawasaki produced the KZ750EE motors until 1988(?) for use in Europe and Asia. Seeing as your motor VIN is pretty high, and the bike probably (although not assuredly) was first sold in North America, I'd guess that motor is from a 1985 ZX750.

Post edited by: Mcdroid, at: 2006/10/04 14:21

Kawasaki calls the monoshock (UniTrak) models Ninja's in the parts diagrams, so an 83 GPz750 is listed as a Ninja.

If it is black and don't have a tach drive then it's a 83-85 GPz750 motor (as far as I know anyway).
My Nephew has one in his 79 KZ650SR

Yep it is black and today I checked for a tach drive and nada. So I guess it must be 83 to 85. In 86 did they go to water cooling? I got out of the bike business in 84 so anything after that I'm pretty clueless. Does anyone here know the claimed horsepower of these engines? As I understand the GPZ's had hotter cams and the heads breathed a little better. I'm just trying to get some kind of idea about what kind of gain I can expect over a KZ 650 engine.

KZ750 74 hp
83-85 GPZ750 85 hp
84-85 GPz750 Turbo, somewhere over 100 hp.

I forgot that the 750 air cooled motor in black continued on in the ZR7.

GPz750 83-85 and the later (after 1980 I think) KZ750 heads are pretty much the same, same size valves, same size ports, etc.
Some models of KZ750 may have smaller combustion chambers.

Post edited by: steell, at: 2006/10/05 22:14

steell wrote:

KZ750 74 hp
83-85 GPZ750 85 hp
84-85 GPz750 Turbo, somewhere over 100 hp.

I forgot that the 750 air cooled motor in black continued on in the ZR7.

GPz750 83-85 and the later (after 1980 I think) KZ750 heads are pretty much the same, same size valves, same size ports, etc.
Some models of KZ750 may have smaller combustion chambers.<br><br>Post edited by: steell, at: 2006/10/05 22:14

85 Hp stock...Hmmmm with an RC 4 into one and 26 mm carbs from a KZ 1000 I would think 90 Hp might be a reasonable expectation. In that little 650 chassis this thing should be a screamer. Might just turn out to be $75.00 well spent. :woohoo: :whistle: