WR450F 2008 DE-Restricting

2 replies to this topic
  • Mr-Brightside

Posted July 27, 2010 - 03:44 PM


I have a 08 WR450. Went to remove pea shooter in exhaust today and found its already been removed....Can I take out the spark arrestor aswell?

I have a white brothers exhaust (with baffle) but was going to run the stock pipe on it as I like to have a quite pipe... or should i just run the White brothers?

The bike needs jetting as it appears to stutter low down.....shall i get it jetted with the stock pipe then put on the white brothers??

Mine is a UK spec bike...I have read about this ASI thing what is it?

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  • firedawg553

Posted July 29, 2010 - 01:52 PM


If you change the exhaust to flow better, then you need to rejet a bit, dont want to take a chance of running to lean and burn up the pistion. The AIS is an emissions thing, it looks like small steel and rubber tubes running to a central valve (4 total i think). This is on the American models, not sure if it is on the UK or not. If so, a AIS removal kit can be purchased to plug it up, however I had to buy an extra hose plug and small clamp. Doing these mods along with the throttle stop screw change, jetting, and grey wire mod really woke my 08 up. The lug in low RPM is gone and the bike runs MUCH better. As for the spark arrester, sorry i don't have that answer, havn't done anything with mine (yet)!

  • Mr-Brightside

Posted August 01, 2010 - 12:17 AM


I removed my spark arrestor and left the baffle in place...Also had it rejetted....seems to run a lot better with that spark arrestor out...the spark arrestor stops exhaust flow quite a lot......I must say I am glad I took it out now!! got the dyno print outs aswell will try and scan them onto here


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