APJ diaphragm differences YZ vs WR

Have anyone noticed that there is a difference in the diaphragms (#31 on microfiche, #9 in users manual) on 2002 (did not checked the older models) YZs and WRs.


5JG-14940-18-00 – STANDARD

5JG-14940-17-00 – OPTIONAL

5JG-14940-19-00 – OPTIONAL


5JG-14940-17-00 – STANDARD

5JG-14940-06-00 – OPTIONAL

5JG-14940-07-00 – OPTIONAL

5JG-14940-08-00 – OPTIONAL

If smaller numbers 06,07,08 represent timing it is possible that this is another way to achieve BK mod result…

[ September 03, 2002, 09:27 AM: Message edited by: sabin ]

C'mon Taffy, JD ... tell me do you know what is this for?


I asked this same question a couple of years ago. JD(?) felt the same as I did, just like you guessed. The "Stroke" of the diaphragm. I talked to a local dealer who had ZERO knowledge on the differences. The only thing to do is buy them all and compare them.

Thanks, but I'll use my "KD" mod instead. There is also the Taffster's mod for the 98/99 and of course Brian's mod (BK) for the 2K bikes and newer.

On three different occasions I have tried to order the different PNs listed under the pump diaphragms with no luck.

I haven't tried recently, but as far as I'm concerned those optional diaphragms don't exist...

The thing to do to compare the WR vs. YZ parts would be to measure the dimple w/ a pair of calipers. I'm pretty sure this is the only difference between any of the diaphragm part numbers.

If I still had access to a WR I'd try this, my friend's '01 is now securely back in his garage though...

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