VERY interesting find!

So, some of you may have read my previous post about the kz700 I got for $250. As I stated in my previous post, i went ahead and ordered stock cylinders and pistons thinking the rings in mine had gone bad causing low compression. Well today I received the parts.

When I first looked at the cylinder and pistons i thought no way are these from a 700. The cylinder sleeves were much thicker than the ones i pulled from my bike. I then compared the pistons and found that the pistons I got were cast aluminum and didn't seem nearly as strong as the ones I pulled from my bike. So i did a little investigation and goggled the part number on the pistons. Turns out this bike has the 810cc wiseco kit in it. NICE!! I measure the bores and confirmed this also. I think im gunna stick with the wiseco pistons instead of reverting to stock displacement.

The entire reason why i bought the used cylinder and pistons is because i figured it would be nearly impossible to find kz700 rings. I don't think it will be that hard to find replacement wiseco pistons on the other hand. Also, the cylinder walls look to really good, you can still clearly see the honing marks. The pistons are stilling int great condition too. The only problem is a couple of rings are stuck in the pistons so Im going to soak them in kerosene and see if i can restore the compression without getting new rings. There is absolutely no scoring on the pistons or cylinder walls.

anybody know the part number for the wiseco rings that come with teh 810cc in case the old rings are too far gone?? also the 810 headgasket??

Thanks

Last I looked they had a nice pdf with all of the part numbers for their piston kits on their web site. Let me see if I can track it down.

Page 67 has most of the KZ bikes under 900cc's on it. I only see an 810 kit for the Kz750, someone else might be able to provide more details.

Edit:

Forgot the link (doh!)

www.wiseco.com/Catalogs/Powersports/CompleteCatalog.pdf

There IS only one 810 kit. The rings are readely available from them. 2717XC is the ring set #.

I order from Wiseco all the time since I'm a dealer of theirs. Their parts are virtually always in stock. Here is a little better link straight to the Kawasaki catalog.
www.wiseco.com/Catalogs/Powersports/Kawa...leStreetOverbore.pdf

You luckey dog.

Thanks for the PDF. The 810 kit price has gone up 100 bucks over the last 10 years. I need to to pick one up soon befre it goes up more.

I have two kits left at an older price I can let you have one at $598 plus shipping. If you are interested you can call me at 630 321 0580 or email me at otto@condormodels.com

Thanks for the info!

Another question, what kind of power increase should the 810 kit give over a stock kz750. The bike I got also came with a Vance and Hines exhaust. Cams look stock, I haven't check the jets in the carb yet. I'm thinking the 10.25:1 compression ratio will greatly increase the power ( 10-20hp??)

I am not sure what carbs the 700 came with but if you install a set of 34mm CV carbs, the bike will considerably more power than a stock KZ900 had. And probably more than a stock 77 or 78 KZ1000, if you install a good set of street cams.

one more question. do you know the service limit of the wiesco piston rings. According to my manual the max ring end gap should be less than .55 mm but thats with the stock piston and rings. I only measured a few rings but they are at about .20mm which looks pretty good in my opinion but i really dont know the exact specs from wiseco.

I had to soak the piston in a cup of pb blaster to finally get the rings to pop out. There is alot of carbon build up and i dont know when this bike was run last but i know it was a long time ago. The head gasket was also blown.

before and after soaking in kerosene (after getting the rings out)



carbon build up



head gasket