grey wire trick

Does the grey wire trick work for wr 400 also? Thanks for all of your help this is great. Also any other cool tricks for my wr 400 would be way cool

yes it works you should de octapuss it and do a wheel collar mod

Deoctapuss would you mind helping me out with that? Explain


you remove a peace off your carb go to something momilkman has posted and it will say deoctapuss you can click on it and it will show you a picture

I also looked or the wheel mod but could not find info on it. Do you have an idea where to look? Thanks again

Definitely do the grey wire mod. It's an easy mod. And, you can tell a difference. From what I've read here, the deoctopuss mod does not increase performance. I just cleans up the cluttered look a little around your carb. You will also want to open your air box, and shave your throttle stop if those 2 things haven't already been done.


Since yours is a 2000 WR400 you don't have to worry about the wheel collar mod or the de-octopuss. Those were both for '98 & '99 models. On the 2000 do the BK mod along with the other "free" mods and you'll be set :). If you need a starting point for jetting look at my sig. Since we probably ride the same stuff/altitudes this should work well for you. I have loved this jetting...some may argue. It's a very personal thing it seems.


ogrebelle.....what exactly does "flipping the ACV" consist of and what does this mod do? Always wondered that when reading your sig and just for the record....your jetting specs seem reasonable for riding at that altitude, but hey, what do I know? :)

"flipping the ACV" consist of and what does this mod do

The ACV DOES interfere w/ properly jetting your bottom end.

By flipping it (on 2K and newer WR's) you disable the ACV.


Sorry I am not sure what the ACV is. Where can I learn what this is and location Thanks for your help.

I'm with you on this one ehh400.....not sure I get the exact procedure for "flippin' the ACV"? Anybody got a quick rundown, in laymans terms, as to how to do this mod? I assume you mean to take out the 3 screws holding the ACV cover on and simply flipping the ACV over and reassembling the cover back on but.... :D? Any help would be greatly appreciated. :)

As I recall you have a little a little hole in the ACV Air Cut Valve which you need to block. This mechanism replaces what was the 'octopus' on the 98 and 99 models.

Waaaaaaaaaaaay back when there was a description on what to do...I'll see if I can find it.

and here is something even better ACV FAQ

You gotta love Utah...July 24th is a state holiday.

All you need to do is flip the ACV diaphram over and replace the cover. You don't need to plug any holes. Once you take it apart and look at its design you will understand why you don't need to plug anything. Note: one side of the diaphram has a small post (pin) on it, this needs to be installed pointing the wrong way to disable the valve, replace the spring like normal.


What spec for the 2000 wr 400 timming? I have it timmed at 12 pins from each other so advanced the exhaust cam one tooth clockwise from its stock wr position. Is this right for 2000 wr 400 or is it different? Thanks again guys this is a real help.

It's been three years since I did this and don't remember, sorry. :) It's somewhere on TT though.


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