Well I put it off all winter and now riding season is upon us here in Western PA. I have a '00 WR400 with WR timed cams, gray wire cut and the airbox lid removed. I have the new GYTR baffle ordered which should be here soon! LOL I am definately going to do the BK mod. Can anyone give me ballpark complete jetting recommendations after this mod is completed to speed my setup/testing time? My altitude here is about 1000 feet with an average springtime temp. of approximately 60 degrees F. with average humidity. I also hate to open up this can of worms again, but I'm considering YZ cam timing. I ride primarily loamy singletrack with alot of roots/some rocks. I'm considering some harescramble racing this year and am about 200 pounds without gear. I am probably of average riding skill. What are your opinions? If you do recommend YZ timing are there any durability problems with this mod? Are there any jetting changes recommended? Please help so I can ride soon.