another ? for all the 300ex experts

[ssduane]

I'm working over a 02 300 ex for a firend and need some advice.

He boughtthe quad used and here is the current state, mods include, a Vance Hines pipe welded on, looks small and is attached to the stock head pipe, high rev CDI, believe it is 1000rpms above stock, twist throttle, 22" ITP holeshots XCT's on aluminum Douglas red's.

I pulled it apart today to see what else was done, not much, carbs got a 122 jet in it, stock gearing still.

So I'm thinking here's what to do, leave the pipe alone, yank the stock airbox lid, throw a UNI filter on it and go up to a 130-132 jet, not sure about the idle mixture screw, where should it be stock or modified?

Any idea on the gearing, leave it alone? The guy doesen't want to chnage tires yet dur to cash flow, but I recommended doing the 18" tires and stepping the front gear a tooth like I did to mine.

Any input would be great. I have a line on some 400ex parts, any idea what I should grab?

Thanks,
Duane

[enduro400rider]

i wouldnt do 18s unless your going to MX the bike, 18s will really slow down your top speed, and cause alot of shifting. as for the pipe i have never heard of that pipe, but i would highly recomend getting a new pipe system either a full system, or if you want you could cut off that after market one you have and just put it on a aftermarket head pipe. the 300 has a VERY restricting head pipe. since you can get 400ex parts, id pick up a 400 carb, throw that on there, with a pipe, id go with like a 130 jet, im running a web cam in my 300 with a full pipe and UNI filter with a 128 jet i beleive, seems to work good for me, as for the mixture screw i just tuned it until i got it right.

[bwamos]

Stock header?.. so start with a 130k (may need to drop to a 128k) main, 2-3/4 turns out on a/f screw. Needle adjust (probably raise it 1 spot) as needed. It's obvious when it's off. 1/4-3/4 throttle.

[Cody_300ex]

i would take the 22's off ASAP, and replace them with 20's. Not only are they robbing power due to more weight and rotating mass, your gearings wayy high. I would pull the lid off, take the choke out and jet the carb accordinaly and you should gain a decent amount of power.