Grey wire... HOLY COW! WHAT A DIFFERENCE!!

WR250F_Rider

Member
May 17, 2001
15
0
I removed my grey wire to the CDI Unit last week and WOW... I cannot BELIEVE the difference this makes... everyone said "Its so much better" But I had no idea it would be THAT much better :)

COMPLETELY removed my big huge flat spot... this bike is SCARY to me now:eek:

Refer to your manual on pg 6-1... it is the wire that is marked "U.S. Models only" Its the grey whire going to the CDI Unit... I know most everyone knows this... but... just in case... I love this bike now.

2001 - WR250F
Removed exhaust baffle (now its too loud though)
removed plastic airflow director from airbox
disconnected grey wire!
 

WR250F_Rider

Member
May 17, 2001
15
0
There have been several posts on this topic here and on thumpertalk.com... check them out to find out... I am not really sure if it does or not. You can check your wiring diagram for wires going to your CDI that are marked "U.S. Models only". If you see this, then my guess is that it has some function to screw the us customers because of emmisions:think I wouldn't just go removing wires however... check and make real sure first, becuase I don't know what the potential dammage for removing the wrong wire would be but i bet it wouldnt be good :)
 

KLX4smoke

LIFETIME SPONSOR
May 16, 2001
159
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Hey, can you guys tell me where the grey wire is on my klx-250? It has a bunch of grey wires but I don't know which one to cut. Someone help please! :p
 

Ol'89r

LIFETIME SPONSOR
Jan 27, 2000
6,961
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Bones.

The grey wire is on the WR 250f and the WR400 and 426f. There is a long thread on Thumpertalk about it. Haven't done mine yet, still trying to learn how to hang on to the thing in it's stock configuration.

According to Thumpertalk, it makes a major difference in midrange and does not hurt the engine.

Ol'89r
 

WR250F_Rider

Member
May 17, 2001
15
0
MAJOR is the correct term... I just cant get over the change... it seems to affect it a little in the top too.. maybe my imagination though.

To my knowledge... this mod is certainly not for klx's, and only for the yamaha 4 strokes... and i dont know if it apply's to the 426, but it definitely apply's to the 250f.... and i dont know about the YZ250f either... it may only apply to the us model wr250f.

here are some posts about it...
http://www.thumpertalk.com/ubb/Forum10/HTML/000004.html

http://www.thumpertalk.com/ubb/Forum10/HTML/000914.html

http://www.thumpertalk.com/ubb/Forum10/HTML/000986.html

http://www.thumpertalk.com/ubb/Forum10/HTML/000757.html

:)
 

KLX4smoke

LIFETIME SPONSOR
May 16, 2001
159
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Sheesh, I was just joking. Didn't you see the :p ? Actually I'm just jealous that I don't have a wr250 myself. If they make an estart wr250 I will sell all 3 of my bikes to get one, until then I'll lust after the 400exc. I'll stop changing the subject now, sorry. :)
 

J_dem_Bones

Member
Jun 23, 2001
197
0
Ol89'r,
Do you have a WR426 or the YZ? As I read all the posts. They were all in the 250f forums. And all the people who cut theres were on WR250's. I can't find anyone with a YZ426 that cut the wire.?? Just WR's. I could be wrong(wouldn't be the first time..;) )
 

WR250F_Rider

Member
May 17, 2001
15
0
I think (I am not sure... those posts on thumpertalk I mentioned probably would say for sure) that this mod works on the WR250 and WR426... I dont think the YZ's have the wire. I THINK... i could be wrong of course.
 

holeshot

Crazy Russian
LIFETIME SPONSOR
Jan 25, 2000
1,823
0
.

Yep, just the Yamaha WR four strokes have the grey wire. If it applied to the YZF's, I'd out there with snips in hand right now. I don't think we all could be wrong. :D
 
Last edited:

wayneo426

Sponsoring Member
Dec 30, 2000
810
1
Sandbar, NY
Only the WR's

The mod will only work on the WR250/400/426. It makes a definite improvement in the mid response.You are able to loft the front wheel a bit easier, and will notice a slight improvement on the 426. On the 250F however, the change is rumored to make a greater impact.
Do not cut the wire. Simply push it away from the connector so that it does not make contact, and snap the connecter back together.
 

Ol'89r

LIFETIME SPONSOR
Jan 27, 2000
6,961
45
Bones.

My bike is a WR in YZ plastic. The thread that I read about the grey wire was in the WR400 forum in Thumpertalk. I read it a month or so ago. Works on all WR models. Like wayneo said, you just have to disconnect it from the connector. Was thinking about installing a bar mounted switch on mine to switch back and forth for different traction conditions.

Ol'89r
 

WRecker

Member
Jun 25, 2001
9
0
Ol'89r,
There's absolutely no point in adding a switch to toggle back and forth. Once you remove the grey wire, you won't want to put it back in. It makes the throttle more responsive, but much more controllable. It is especially important in that it allows you to run a gear higher in low traction situations. If it starts to bog, you can pin the throttle and not have it puke on you. It will just hunker down and keep pulling. After having removed the wire on my WR250, I'd never, EVER consider hooking it back up. If you do a search over at Thumpertalk.com, you find tons of info on the grey wire, and also another poster who had the same idea as you.

Yes, the grey-wire fix only applies to WR's (all sizes), and then only on US bikes. It has the biggest effect on the littlest WR, and is the simplest and cheapest (as in FREE!!) way to unlock more power in your bike and get rid of the annoying flat-spot that appears after you remove/trim the throttle stop. It's there because of the emissions/sound requirements the EPA has imposed on off-road (not closed course) bikes. If you pull the grey wire, you MUST remove the baffle from the stock muffler, otherwise it won't run worth a darn. I even tried modifying the stock baffle (swiss-cheesing it with a bunch of holes in the end plates) but it was still too restrictive. Go with a Vortip, or an aftermarket exhaust if you need it quieter.
 
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