I have a 03 wr450f and im doin all the mods to it and im wonderning what is all changed and affected when you cut the gray wire?

some say it does work,some say its a waste of time


The gray wire is part of the ignition mapping. WR has it the YZF does not. Cutting the gray wire advances the ignition timing to YZ specs. Some like it others can't tell the difference. I suspect that if you remove the baffle and change to YZ cam timing it will make more of a difference. Check Motomans site here at TT, he covers that as well as the other free mods. Have fun.

I have my WR450 grey wire switchable and I can't tell the difference. Others say they can.

I also have a 03 WR450, have about 80 miles on it 40 of which were motorcross racing. I was riding a KX500 (very fast bikes) until it put me in the hospital for a month this spring. I am just starting to ride again, so I am sneeking up on the power of the 450 as I get used to it.I have not cut my gray wire yet. With the mods I have done so far I don't see a need to yet. I threw the muffler insert in the toolbox (now it sounds like a real motorcycle)YZ throttle stop and the air baffle remover(which is a pain).

It still felt weak compared to the KX. The thing slid out fron under me trail ridding one weekend so I decided the stock tires had to go!! I installed a set of Dunlop 756's, it doesn't even feel like the same bike. It will stand up in any gear now you can feel the power. The stock tires just couldn't bite into this Michigan dirt. So I have decided not to cut the gray wire at this point or change the cam. It ran with the big boys racing it these last two weekends. Boy it sure is fun to be on the starting gate and watch everyone kicking thier brains out starting thier bikes. And then you just reach up and hit the little gray button and smile. :)

mine would miss and sputter at small throttle openings(not accelerating hard) while cruising, until i disconnected the grey wire.(w/other free mods done)

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