Engine help

I have a 1978 kz650 not too sure wich model it is but I received the bike two years ago and the bike was in such rough shape that i just decided to not even try to start it and just tear it apart and rebuild but then found out that you cant buy the 650 pistons for that year brand new anymore so I when to this Jap bike bone yard that we have here in Regina Saskatchewan Canada and the guy asked me the year and what it was looked in his book and told me that the pistons and rings have been discontinued. He then told me that I could bore the cylinders out however many millimeters and make it a 750. Which I have no problems with but I would like to know what book he looked in because I would need to know more than just how much to bore the cylinder out cause now I have to change alot of parts and this book he has must tell you what you have to do for the rest of the parts is you change and go to a bigger piston. Any help would be greatly appreciated.

As pretty much others have mentioned.... KZ650 pistons/ rings hard to come buy....

Dynoman out of Texas (Speak with Buzz) has other kits.... 700cc kits (pistons, rings, pins, clips & gaskets) Cylinder Boring only....

www.dynoman.net/engine/pistons/kawa.html#650

OMR

According to Kawasaki.com the STD rings (part # 13008-059) are available. NOS standard pistons are almost always available on eBay. I don't believe you can bore a 650 engine to 750 CC's and still have any cylinder liners left. I would question that this guy actually had a "book" that gave the information he was feeding you. If he did, he should be willing to give its title, publisher, and print date. I take it he didn't actually show you the book? BTW, if you can show a pic of your bike we may be able to identify the model. Ed

hey paddy i think i know who you are talking about i think ebay is in your future lol i am in regina as well its hard to find parts around here

so if I was to go to the 700cc then are you able to use same crank, cam oil pump and stuff like that I mean this guy told me that he had lots of parts that I could swap out but I mean I dont understand where he is coming from because all my parts look in good shape except the oil pump and pistons

Before you take drastic measures, contact Z Power in Leigh, Lancashire UK. They are Kawasaki gods and are one of the only authorised parts only dealers. I was looking for a really out of date factory manual and actually contacted Kawasaki UK to see if they had one, they didn't they but pointed me in the direction of Z Power and they said......how many do you want?
They have a website www.z-power.co.uk well worth a try for all those bits that no one else has or says you can't get.

As for boring out the cylinders, they won't go to 750, 720 is as big as it gets and Wiseco do a piston kit for that.

you could also go to fast cycle sled 352-5533 they used to own northgate kawasaki many years ago here in regina

You can put 750 barrels on a 650 block and be done with it. You will have to clearence the bottom of the barrels slightly to mate to the block. The 650 and 750 four blocks use the same cases and internals. You could even go one up and bore the 750 barrels to 810cc's. If you do that I would use the 750 head also because they flow more than the 650 heads. A few members here have 810cc 650's

The 650 and 750 four blocks use the same cases and internals

Well, kinda/sorta

A 650 that has no kick starter (81-82 and newer) is the same as the 750 motor with smaller displacement. If the 650 has a kick starter then it has a roller cam chain instead of the HyVo type cam chain of the later models and the 750's.

83-85 Zx750A (GPz750) head and block will work on the later 650's that don't have a kick starter, but not on the earlier 650's.
80-83 KZ750E and KZ750H cylinder blocks and heads have provisions for the roller chain used on the early 650's.

I've got lot's of 750 four parts