Jump to content
Sign in to follow this  

Mods for my 01 426

Recommended Posts

I am very new to this site and have been very impressed by all the info that you guys share, in the last three days I have filled my head with all this info and now I am ready to spend the weekend trying out some of the free mods that are talked about. My bike is a 01 WR426, air box cover removed, FMF power core, and stock jetting, which mods should I do? grey wire, BK, ACV????

I am also looking to my suspension done, if any of you so cal riders have some good recommendations it would be greatly appreciated.



Share this post

Link to post
Share on other sites


There has been some generic jet specs thrown around alot. Look at the jetting topic that is approaching 200 replies (takes 20 minutes to download w/ cable modem!!)

The gray wire is a must do. Do a search on it. You will find the location and type of connector it is housed in.

The air cut valve (affectionately known as the octopus) seemingly masks adjustments done w/ your pilot (fuel) screw. The Kouba tool you are getting connects w/ this screw. The YZF250 guys have done considerable discussion on it. You may find answers about it on that sight as well. The trick for your bike is to gut the thing.

The BK mod will allow your accelerator pump jet (APJ) to operate the way the engineers hoped it would, not the unfortunate way it works. It allows you to set the timing of the squirt relative to the postion of the slide valve, and the duration of the squirt. Concensus on the duration is ~0.5 seconds.

Good luck Jay!!

Is that check for $13.00 in the mail?? :)


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this