Someone please tell me why there are two sizes of spacers. Once is 25mm and the other is 30mm. I came about this when I was trying to swap sprockets onto my spare hub.

Spare hub was from a 2009 with a 30mm spacer whereas my 2010 came with a 25mm spacer.

http://i2.photobucket.com/albums/y5/cuongnutz/Ninja%20250/12EAAA7E-791E-4B1D-BC59-FAB8C9DA5EBD-10437-00000C28E8114B9B_zps3e776e83.jpg

pn: 42036

http://www.partzilla.com/images/diagrams/kawasaki/I15/I1527/F2240.png

You mean the I.d.? As in the axles are different sizes? Or just oal as your pic shows?

Sorry I was referring to the length. Inner ID for the axle is the same between the two.

Someone please tell me why there are two sizes of spacers. Once is 25mm and the other is 30mm.........

1995 Ninja 250 and earlier models came with that part measuring 25 mm.

Starting in 1996, all the pre and new-gen models came with that same part measuring 30 mm (same as Ninja 500), even when they kept the same Kawa part code 42036-1217.

If you Google that part number, the engine will find both lengths.
That may have been the reason for a 25 mm being used in a new-gen. :confused: :confused: :confused:

Over those years, the only other parts of the assembly that changed were 41068 (axle), 92143 (bearings separator) and 42033 (coupling assembly).

Crazy. How do you know that?

First gen spacer is longer. I have a couple hubs I put gears on. Makes changing sprockets super fast. One day I could not get the wheel in. That is when I found out about the difference.

Good to know Eric! I'll see if I can get it swapped out for the correct one