What jetting to use with a T4, K&N, XRCAM

[generalg]

My new 99 EX has a Pro Circuit T4 slip on, K&N air filter, outwears, no air box lid and an XR cam. Anyone know of what jets work best in this situation? Currently is has a 165 main, not sure what it has for the idle jets or the needle position. What is everyone running with the similar setup? I noiticed in a earlier edition of DritWheels, during the pipe shootuot the T4 used a 155main and K&N..... Any help is greatly appreciated.

Thanks

[Leo]

I've got a 162 in mine (T4 slipon, stock intake) and it's a tad rich.. I've got some pilot jets kicking around, but I haven't had a chance to fine tune the jetting.

Leo

Why doesn't any one tell what elevation they run at? Jetting issues would be a heck of a lot easier! Try a #40 pilot and #158 main, needle in the third groove from top. Stock is second groove.

[Atomic83]

2slow do you have a removed airbox lid?

[generalg]

I'm sorry, I live here in Kansas, elavations is I think 3000 above sea level. I will try a 158. I think it is way to rich right now with the 165, because it shoots black smoke a bit.

No airbox lid. My elevation is around 2000' but I ride anywhere from 500' to 4500'. I started with #160 and it worked really well except that when in warm temps my top end was kind of flat in 4th and 5th gear. Tried a #162 and it was definately rich. Dropped to a #158 and it runs very well now and the plug looks great. I can't say for a fact but would suggest to any one that installs a pipe,or no airbox lid, or a different airfilter, to install a #40 pilot jet or at least turn the idle mixture screw out an extra turn. :D

[rhandw69]

2slow,
Im over here in Tacoma, i have a 416 piston kit, and hopefully in a week i will be installing the xr cam. (wb all around)
Im curious what your elevation is over there in St John. I have to run a 170 main when im on the coastal dunes. However here and the further inland i go, i have to drop to smaller sizes. This past weekend at a hare scramble, i had to drop from my 170 to a 160. There is no way i can run that lean at the dunes. It runs WAY to hot, and my plug reading would be very very white.
Here in Tacoma with a 170 main, my plug reading is actually rite on. However,,
From 3/4 to WOT, it really pops, and sputters alot. When i drop the main jet, the further down in goes, the more the sputtering goes away.
It seems the only way for it to quite sputtering and shutting down after hitting WOT is to run lean.

RHAN;

My elevation is 2000' at home. I've got a quiet core and spark arrester so the exhaust is choked up a bit more than most on this board. If I didn't have a cam, I probably would have to run a #155 main. Or, if I run the silencer only, I would need to run a #160 or #162.

Where is your needle set? Try a#165 main and raise the needle one or two notches. You can try a #170 and lower the needle down a couple of notches. It's all academic anyway because it will probably change a little with a different cam profile.

Remember-- the main jet is only flowing at capacity from 3/4 to WOT, so sounds like your rich on top and good in the middle. That can usually be adjusted with the correct jet and needle adjustment. BTW-- if you haven't changed the pilot jet yet, now would be a good chance to try a #42 or maybe bigger. That would help startup, idle quality, and off-idle response.

I'm not an expert but I like to experiment with other peoples money! :huh