250-500cc WR300 Wossner piston/pro x bearing fitment issue

Hi guys as a few of you are aware my wr recently suffered a lean seizure. I have just gone to fit my new Wossner piston part number 8250 DC and found that it binds on my pro x gudgeon pin bearing part 21.1303.

Has anyone else experienced this? should i be using a different bearing with the wossner piston?

You can get narrower bearings, supprised you didnt just order one with the piston.
Think the common size is 18/22 but that may be a made up figure from the land of noncense did you know 99% of statistics are made up??

Oh i would get a replacment bearing from wossner, thanks for the heads up an any seizures suck

Ordered the piston kit and bearing together, they sent a pro x bearing instead of wossner. I will contact them tomorrow, I believe the wossner part is N1020. Just have to find someone who has stock in OZ now. May even try the bearing shops.

whod you get piston kit through Jaz & how much?

Well thats their fault and should if checked compatability, sucks that your now down a bike till they get a replacment out to you.

Through GC Motorcycles, great guys to deal with, not their fault, the wholesaler they deal with import Wossner and Pro X. Simple mistake. The kit with full top end gasket kit came in at $285.

cool i might check em out

I only paid 180 for. Top end, and head and base gaskets!!! Pro x . $285 is ridiculos!! I race b hare scrambles, and never had any issues.

Australian prices suck, however that was a full top end gasket and seal kit including all the power valve seals and gaskets.

I have some new info, you can use Pro X part number 21.6320 with the wossner piston. It's 2mm narrower than the 21.1303.

She's back together, 1 clip richer on the needle, made a gasket to go between the reed cage and boot, sealed airbox boot in properly as the factory effort was below par. I used the thinner of the base gaskets for a compression bump. Greased everything properly whilst putting her back together, it's amazing how little grease they use in in the factory. Will mix up a fresh batch at 32:1 tomorrow and run her in.

32:1 , I run mine at 50:1 and runs great. @50hr mark i replaced piston with wossner and had to get the boss machined to fit as bearing wasnt available to fit. Pain in the A#$..