Grey Wire

I am seeking optimal performance for my WR426 2001. I read below that someone suggested disconnecting a so called "grey wire".

Can someone tell me what the function of the Grey Wire is, where is it located (best disconnection spot), can it cause any damage? Tks!

grey (gray) wire is apparently only on the U.S. bikes. It screws up the ignition timing to meet U.S. emission (or noise?) standards.

Use "Search" for the grey wire.


'99 WZ/YR (you choose!) with ALL YZ mods, de-octopused, DSP Doug Henry airbox w/ velocity stack, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, OEM YZ tank, IMS YZ seat.

If your WR is a non-US model - forget it.

The grey wire is for detunign the US models only.

- Sean

Photo of Gray wire on WR400F 1999 model. Under Tank (Right Side)


now that is a nice picture Bill!

I concur about the Pic. No duobt which wire is grey. Or is it gray.

PyroTed, see the double connector? 1 black/white wire & one grey wire-that looks white in this picture, closest to the blue frame. Cut or remove the grey wire from the connector, insulate w/ elect tape, you are set. Now go roost!!!!!!!

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