KZ550 - Anybody can identify this Pistons???

Hi,

I'm from Uruguay and i recently brought a KZ500 to restore (i brought it cheap to restore all the bike, because i like to know what kind of bike i'm riding ).

The last month i brought some pieces in ebay, and today the parts come to my home; the parts was supposed to be KZ550 parts and i know that there is no problem to put 550 piston´s on KZ500.
But when i measured the piston's i noticed that are 60mm piston, and looks some strange.
Anybody knows what kind of pistons are?, because i need to buy the rings and i see that the compression rings are different (one is thinner).
Thanks in advance.
Flavio.

Hello Flavio,
Welcome to KZR !
I have a Z500,and a manual, and it tells me that the standard piston for the Z500 is 55x52.4mm.
For the KZ550A1 is 58x52.4mm.
The 1st oversize piston is +0.5mm. 2nd oversize is +1mm.
So sorry, I can't identify the pistons in your post,but they have a different skirt to mine,if thats any help.

Thank you Sparky for the data

I think that the better is buy KZ550 Pistons and expand my cylinders, because 60mm to the original 55mm is too much.
Do you think that my cilynders can go to 58mm (550 size) without changing the original Cylinders?

I have a Z500 which has been rebored to 2nd oversize and that makes 516cc. So No, you can't bore the sleeves that far but... I had access to a Z250 and tried the pistons on my rods, they fit. So if you can get 4 oversize of them with rings then the man will rebore to them.
Or, you could find a cylinder block from a KZ550 and use that.Use the 500 head.
[you would need to drill the main jet out from no 90 to at least 95].
Oh, and a bit of carb adjustment:blink:
Regards.Peter.

Thanks you Sparky.

I think that i´m needing to get a KZ550 Cylinder Block .

BR, Flavio.

I have another question, anybody know if GPZ550 pistons will run fine in the KZ550 Cylinders?

Bore and stroke are the same KZ550 to GPz (A, B, C & D1, H1, H2). Major differences in the engines are cams and carburetion.