Are the 1973 z1 pistons different????

Are 1973 z1 pistons different from all of the other z1 bikes. The reason I ask is because I bought a 1973 bike with one piston being different and when I check the compression one piston has lower compression, not sure if it is because of the piston or because of valves or what ever it can be. Please let me know

I think pistons for the Z1/Z1A/Z1B/KZ900 are the same. If you have mismatched pistons then I'd check the diameter of the bore to see why either one, 3, or all pistons were changed.

Do you think that a different piston could change the compression from a differnt year z1 bike?? When I look online for new pistons, they show the pistons fitting all year z1 bikes, but not sure if the factory had all same pistons on all years.

00. wrote:

Do you think that a different piston could change the compression from a differnt year z1 bike?? When I look online for new pistons, they show the pistons fitting all year z1 bikes, but not sure if the factory had all same pistons on all years.

Kawasaki ( www.kawasaki.com ) shows the same part number for standard pistons for Z1/Z1A/Z1B/KZ900

It is possible for a piston with a different shaped top surface to change compression numbers...you need to find out if they are aftermarket pistons and who the manufacturer(s) are. You might start down that road by measuring the diameter of the bore to get some ideas of what the previous owners have done to the bike.

I just read your other thread...so you re-ringed but used the same pistons? And one of those pistons differs from the other three...if so, how exactly does it differ?

Do all the pistons, have the same wrist pin height?