Rebuilding wr400. Couple of q's.

1 reply to this topic
  • drucer

Posted January 16, 2010 - 06:01 AM


Hey guys

Just about to go right over my wr400 00 model.The bike is stock except exhuast and freemods, barkbuster etc

Just wondering if a 426 head goes onto the 400 block??

ALso i know you can change a 426 into 450 ergos with new tank, subframe etc but can you do it with the wr400 as well.I was thinking yes as i was pretty sure the frames are the same but just double checking.

If anyone has any good mods that arnt to dare also post them up>i was thinking apgrade of rotor size.High compression piston, auto deco cams. etc.
All in all i am going over the bike to get more power, neaten it up and imporve performace

thanks guys

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  • Math

Posted January 16, 2010 - 12:53 PM


Here are some mods I did to my 426 that were absolutely fantastic.

IMS Ty-Davis fuel cell (you can get them from zipty racing)
This will require that you go to a YZ seat. Guts racing soft seat is the one I have and is tough to beat in terms of comfort. This will also require that you buy a bar mounted DRD hot start cause you won't be able to access the red button with the new tank.

YZ-timing... you can find a lot of info here.

FMF Q exhaust

As for carburation, I did the air cut valve mod, o-ring mod, adjust the squirt from the fuel pump. There is a lot of info on jetting these bikes in this forum.

Enduro engineering hand guards, Devol rad guards and skid plate, Renthal bars

Plan to do soon:
Sidewinder chain/sprocket
TM Design chain guide
Sunline levers
Galfer brakes

I ride kenda trackmaster II tires front and rear and they seem to be incredibly cheap, incredibly efficient and quite durable all at once...


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