Number on piston?

Hi guys. I just cleaned the pistons on my 80 Kz550. There is the number 50 marked on top of them. Does that mean it's bored 50 over? I noticed that a stock piston has no marking on it.

Thanks

Most likely 0.50mm over. Not 50 thousandth of an inch over.

Factory offers two sized over stock, and I believe they are in mm.

Thanks guys. So when I buy new rings I need to get 2 over? (2 over = 0.50)

:huh:

It seems like most KZ's use .5mm as the first oversize and 1mm as the second oversize. I don't think I have seen any .25mm oversize, so you would have 1st oversize pistons.

Ummmmmm. :huh: Now i'm confused. It doesn't take much.

Everyone is saying the same thing, .5mm=.50mm

I think you probably need the following part number (4 each):

13025-1010 RING-SET-PISTON-L

.50mm = .020"

Aaww crap!! I was editing my post and accidentally deleted all my references!!

Short version:
There is a seller on eBay that is selling a .50mm oversize piston for a KZ550. If you copy the part number he has listed and paste it in the "Part Number Search" block at Ron Ayers it will show you the part number that superceded that one, then go to Kawasaki.com and look up the part number for first oversize (L) pistons for your bike, and you will see that the part numbers match.

50 = .50mm = first oversize = I QUIT!!!

Can't believe I had to type all that twice. now my two typing fingers are all worn out :laugh: :laugh: :laugh:

Post edited by: steell, at: 2006/11/14 23:07

Aaww crap!! I was editing my post and accidentally deleted all my references!!
Can't believe I had to type all that twice. now my two typing fingers are all worn out

I hate when that happens! :laugh:

kinda on topic questions: are the kaw OS pistons also made by ART (same as the stock ones)? and are they generally the same compression ratio?
Scott

77KZ650 wrote:

kinda on topic questions: are the kaw OS pistons also made by ART (same as the stock ones)? and are they generally the same compression ratio?
Scott

The 750 twins and fours are, I don't have first hand knowledge on other models though.

They are ART pistons for the OEM oversized for the 900/1000 I believe... also same compression ratio.

Post edited by: wiredgeorge, at: 2006/11/15 10:00

Thanks steel. Let those fingers rest for a while..