i hate jetting

[trxex]

ok today i brokeout the radar gun and went to the L.I.E service road(woods trail unrideable due to snow).my pilot is set,my needle clip is also set.so that leaves the mainjet.i started with a 152 main and did 3 runs best run was 61.4 mhp.i did a proper plug check .the plug was white. so i skipped 155,158 and went to a 160 main first run was 66.4 mhp,second run was 67.1 mhp.plug had a very light gray to it .mods: header welds grinded & polished, white brothers e-series s bend 12 disc with spark arrester, uni air filter.12-1''holes in air box lid with uni inserts,40 pilot needle clip stock 3rd clip setting 160 main(for now) 20-11-9 holeshots(1'' taller than stock).43 'f temp @ sealevel. N.Y, L.I power feels good so my question is (2)1 does anyone know what a bone stock 400 ex top speed is .iam 220 lbs,2 does 160 sound right ,(i know each machine is different).i also swiched to amsoil 10w40 full synthic motorcycle oil ,anyone using this oil

[speedjunkie]

Sounds like you are running pretty good at top end:D Just remember, your top speed will never change until you do gears. My 400ex does about 67-69 miles an hour on the flats.

[Steve-o 400EX]

It sounds about right for the top speed, especially when being run by a guy at your weight. Do a run with someone a little lighter and i'll bet that it will be much faster. Your jetting sounds about right.

Good luck.

[trailburner]

Yes 160 sounds right,im running the same pipe setup as you with a K&N filter[ lid off] & mine runs great with a 160-165 nice tan plug & you prob not going to get that much more top end unless you change the gearing....

[trxex]

i agree ,top end will not change unless gearing does. iam only useing topend ##s to dial in my main jet, I.E if my jetting is 100% correct and my top speed is 67 mhp then by going richer or leaner the top speed will drop.so iam trying to find the best topend speed along wiht a good plug reading for jetting only.

[Colby@C&DRacing]

Just wanted to let you guys know that when jetting you can never correctly set the needle before the main jet. The main jet must be dialed in before setting the needle. I alway set the main, then the needle and then check the pilot and air fual screw again.:) One really handy tool for jetting is an air fuel ratio sniffer. K&N makes a nice one that we sell for $200. It takes all the guess work out of jetting.:D

[trxex]

i was thinking about a fuel air ratio sniffer but if iam correct the sniffer probe goes into the tail pipe opening.but the whitebrothers e-series uses diffuser disc and has no real opening to install probe.is there any way of useing the k&n sniffer on this type of pipe.if so i would be interested in the unit