Piston info for 750

I am trying to find some piston, but the online sites dont help with their lack of discriptions.

Kawasaki list the pistons as STD, L, and LL. but say with is oversized and how much. Of course they dont tell you witch one is what numbe either.

I need one standard and one oversized. The standard is easy, but which part number is 0.25mm oversized. any ideas?

Are you going to try and run one STD piston and one oversize piston in the same engine? If you go oversize, you really need to do all 4. You'll need to have the cylinders bored to fit the oversize pistons, as well. It might be cheaper to find a used set of 750 cylinders and pistons on Ebay.

first is it a 4 or a twin? either way i saw many pistons on ebay last night when i was searching for 750 jugs.

Howevre i believe if you go oversized on one piston you need to on all.

cgi.ebay.com/ebaymotors/Kawasaki-KZ750-T...temZ2491518451QQrdZ1

a set of .040over pistons not bad if you have a twin!


ohhh and here is your .025 kit; they have 2 instock!

cgi.ebay.com/ebaymotors/New-Kawasaki-KZ7...temZ4579813064QQrdZ1

Post edited by: hardr0ck68, at: 2006/03/05 10:24

1983 Kawasaki Spectre KZ750N (currently a puzzle on the concrete floor)

It's a 750 four.

Might be a long wait for some to show up on eBay

Std is standard bore.

L is .25mm (.020") oversize
LL is .50mm (.040") oversize

They are rather expensive if you buy them from Kawasaki, ~$225 for just the pistons and another $120 for the rings online (cheapest prices I have found), and I think the piston pins are around $40. That's somewhere near $385 for stock parts. A Wiseco 810 kit (pistons, rings, piston pins, and a head gasket) can be bought for ~$360
These prices are for the US, if you are elsewhere then they may cost more. If you buy from a Kawasaki dealer in the US, then the parts will be about 50% higher.

Post edited by: steell, at: 2006/03/05 10:56

It is a four, i wish it was a twin.

What me and the machine shop are going to try is to only oversize one cylinder. To save money from boring out all four. We believe we can balance the oversized piston to match the other three. keeping the engine in balance.

Im on a limited budget at the moment and the balance wont cost extra. boring out all four will cost.

Id hate to buy a cylinder block from ebay, only to be in the same boat im in now. one cylinder had water sitting it at some point in time, and has to be bored out. the other 3 are perfect.


Dont suppose anyone has a stock piston they are planning on tossing out.
For a four of course.

steell listed....
Std is standard bore.
L is .25mm (.020") oversize
LL is .50mm (.040") oversize

Thanks for this info...exactly what I was looking for.

Just curious, had anyone bolted a twin in place of a four that is shaft drive. and mantained the shaft drive. Im not thinking this would work, but didnt hurt to ask.

I wonder what the possibities of finding a stock sleeve would be? Or maybe you could find someone that is going to install an 810 kit and just swap blocks with them.
If you are going to bore one cylinder why would you want another standard piston?

Major (and I do mean major) work would be needed to install a 750 twin motor in your 750 four cylinder chassis and converting it to shaft drive. The motor won't even fit into the frame, it's to tall.

You live in Europe?

Hmm, your IP is on Cox so you are in the US, so are you just visiting or did you aquire a European model bike in the US? Reason I'm asking is that I might be able to help you out if you are in the US

Post edited by: steell, at: 2006/03/05 17:07

Meekrat wrote:

We believe we can balance the oversized piston to match the other three. keeping the engine in balance.

:huh: how? ..even if they weigh the same, wouldnt that piston be generating more force on the crank than the rest, and posibly twist it a bit? sounds like jetting would be tough too... maybe I'm paranoid, but I think you might have a few problems with it. but good luck
Scott

There is less than 1% difference in bore size betwwen stock and 1st oversize, so I don't think there would be a measurable difference in power output. As long as it is weight balanced then one piston oversize is not going to be a problem. Sounds weird though don't it

Well a good reason for posting here is to get opinions from ppl that know more than me about this issue. I am learning alot about my bike from input on this forum.

I did not even consider airflow into my problem. might be more trouble than i thought.

i broke two of the piston skirts by not paying attention. i need one std to replace cyl #2, and cyl #3 was going to be bored out.

I am just trying to reduce cost, so if someone wanted to trade I would be up for that. I would need a block that only needs honed though, otherwise id be back to square one. This block is stock bore, but needs to be bored .25mm to smooth out the number 3 cyl. And mabye they would part with the old pistons.

I live in Arkansas, I dont think this is a European bike. How would I tell?
Here is a photo of the engine tag.


Post edited by: meekrat, at: 2006/03/05 20:28

Post edited by: meekrat, at: 2006/03/05 20:34

I got you confused with someone else that has a GT750 shaft drive, so as usual I'm the one that's confused

i have 4 stock pistons for a '80 750. give me a u2u