Yamaha part numbers -- WR400 -> 426 Conversion

3 replies to this topic
  • gearb0x

Posted March 22, 2007 - 03:18 AM



I'm doing a 426 conversion on my 400 and i got a quote for all the bits using new OEM stuff from a 2001 WR426. One thing i noticed with JJHayesIII's list of part numbers he has posted a few times on the forum is that the part numbers for the piston & crankshaft assembly are different. Which after checking the catalog his parts were for a 2002 model.

Here are the part numbers:
Crankshaft Assembly
2001 WR426: 5JG-11400-10-00
2002 WR426: 5JG-11400-20-00

2001 WR426: 5NG-11631-00-00
2002 WR426: 5NG-11631-10-00

So my question is. What is that 3rd number for? are these parts actually different. Does anyone know of any changes that would have affected these parts between 2001 & 2002.

Just wanna make 100% sure before I order the parts

Phillip Savage

  • 1rkcooper

Posted March 22, 2007 - 06:54 PM


Check this link, it should be of some help doing the conversion.


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  • JJHayesIII

Posted March 23, 2007 - 12:12 PM


I don't know the answer for sure, but the assumption I made going in was that it was just an updated part, so sometimes when you try to order the 2001 part #, they'll automatically replace it with the 2002 #, since it was originally the same part, but has been revised....

  • gearb0x

Posted March 26, 2007 - 04:45 PM


After going through the part numbers for 2001 vs 2002 426's for parts ill be ordering the only ones with different PN's are the crankshaft & piston which JJHayes has confirmed work ok for the 400-426 conversion, so i guess ill use the updated part numbers :bonk:

Thanks for the help guys


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