Grey wire mod on UK WR450s

My apologies for such a newbie question, but I have searched fairly far and wide and still don't have a definitive answer.

Does the grey wire mod apply to UK/Euro WR450s or just the US models?

Some people seem to advocate doing the grey wire mod on UK bikes, but looking in my UK 2007 WR handbook I can't see any mention of the mod. Mind you, I don't think it mentions the throttle stop either, but that certainly needs doing on UK models.

I've also heard people on other sites suggesting that the mod doesn't need doing because emission requirements are different between US and the EU.

A third school of thought seems to be that pre-2003 UK bikes didn't need the mods, but more recent UK bikes do need the grey wire removed.

If anyone could clear this up once and for all, I'd be really grateful.

(Also, on a tangent, can anyone tell me whether if I fit an FMF Q4 slip-on and open up the airbox if I'd need to fully rejet or just tinker with the fuel screw?)



if it is an older wr the wire is under the gas tank in the white wire connectors,if it is 07 or newer it is under the number plate on the left side if your sitting on your bike .

as for the exhaust quest,yes you need to jet richer,buy a jd jet kit and follow instructions+they give you a winter needle for cold days.good luck

and for the throttle stop screw you need to take it out and shorten it to one inch total leangth of screw,or buy one made for a yz,they are already short.

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