Grey Wire

Gray Wire,

Suggestion: If you install a switch flip the switch on and restart the bike ride a few miles and then flip the switch off and restart or reboot the system and ride the same few miles to get a good test. If you do this let us know what your finding are.

This 4 stroke is all new to me I am an old 2 stroke person I go back to the old Greeves days if anyone knows what they are or should I say the old JN Roberts day when the desert was all open in Calif.


Gray wire,

Oh I forgot to mention that I have a 2006 WR450F and my Gary wire was disconnected and the throttle stop was removed before I picked up the bike.


I have read this whole thread, and other's....And I guess i missed it somewhere.

(Sorry for this question in advance.)

Can I just take out grey wire and that's it? No rejetting or anything?

What will I notice without this wire?

Thanks for your patience.

On the WR250F the grey wire mod is the way to go, But on the 450 its not that necessary to do it, If your riding real hilly ground then you want smooth power from the 450 keep it connected, If riding open fast ground then the mod isn't needed at all cause your on the pipe more.The mod only effects the power down low after half throttle the mod does nothing.

That's weird, I didn't notice much change at all from 0 to half throttle but my WR450 in now a beast from half to full throttle after doing the grey wire mod. I definitely recommend it!

Help me understand this, please. If I disconnect the grey wire on my 06 wr450, it will change to YZ timing? Will this change the way my bike climbs and motors up hills at slow speeds?

Hey A-ron, you could check (for 250 but same principle) and also do a search, but to be brief:

Grey wire earths an alternate ignition maps for the WR. The OEM map has the higher RPM advance retarded (there are some informative graphs somewhere) which makes the power soft from about 4500rpm up.

The grey wire pulled allows access to an alternate map with the "full power" ignition advance at higher RPMs. There ignition has both TPS and RPM sensors for map access. The grey wire"mod"produces a significant hit and more power up the rpm range.

This in no way changes the cam timing...this is not an option on the 05/06 WRs. You have to chnage out the cam (hot cam or YZ spec) for this - search if you want to go this way, there are many previous inputs on this.

The grey wire mod cannot be live switched with the motor running. The CDI reads the appropriate map and accesses it on power up. You can have a switch but you have shutdown and depower the cdi (ignition switch/button) to work it.

This is in contrast to VORTEX which have an on the go (2 of 10) map ignition selectable CDI.

Hope that clears it up for you?? :thumbsup:

Thanks, OneToGo...Crystal clear now!


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