250-500cc 2012 WR300 piston kit options and part number please?

Hi guys as stated in my other thread my top end is cooked. I was looking up the part number of the piston that had been installed in my bike and it appears to be a ktm part, PRO X 6394.

Can anyone give me a part number for the husky equivalent?

The Pro X piston was sized 71.95mm, so you probably have a 'C' sized cylinder (check for a stamp near the reed cage).

Here are the OEM (aka Vertex) part numbers and sizes:
A = part #8000h0670/1 (71.935-71.945mm)
B = part #8000h0670/2 (71.945-71.955mm)
C = part #8000h0670/3 (71.955-71.965mm)


It also happens that i have a brand new OEM 'C' piston kit for sale in the classifieds. Has everything needed except gaskets.

Weird all these 300 problems.... my 09' had 140-150hrs when I sold it and I never had one issue. And I, unbeknownst to me, rode it around the sierra's for 3 weeks with a cracked radiator constantly running it dry.

Seems like anyone with 09's and below have zero issues. After that its hit and miss.

after 2010 with new ducati ignition maybe cause of problems-mines sweet too!