Heard Something Strang

[RUFIO]

If i run my e-series slip on, with no air box lid...could i leave the stock jets in? b.c K&N only makes stage ones for a 250ex..and i heard that you dont need to rejet unless you change the headpipe...what damage could happen if i dont rejet..and you cant really move up in jets b.c no ones makes them!.....can any one help?..BTW, you could make a 250ex a manuel clutch could you?....i dont want a 300 or a 400 so i dont wanna here ur Shyit

[phatswinn]

go to your local dealer and get sizes 1-4 sizes bigger than stock for the main jet, the k&n kit is too much money

[TRX250EXER]

you can buy jets from your dealer. YES you will need to rejet with the e-series. even tho its say you dont need to. probably gonna need 2 sizes up at least. I have a 98 in now and the stock was 95. runs good now but I need to adjust my vavles. may change after that.

[RUFIO]

The higher the jet..the better proformance?? then why dont i stick like a 102 in there?

[TRX250EXER]

no no no. The higher the jet the more fuel it lets in. When you put on a pipe and air filter it increases the air flow. when you increase air flow you need to also increase the fuel flow or you will be running lean and overheat the motor. BUT NO... you cant put in a too big of jet. Then it will run rich. too much fuel. But a 102 might be about right dont know yet. you just have to play around with the carb and see. there used to be a great description on here in the tech part about rejetting. it describes what everything does in a carb. If you dont feel comfortable about doing it yourself I suggest taking it in. sometimes it can be a pain in the arse to get it dialed in just right.

in my 250ex and it runs perfect whith the t4 and k&n filter. Also went up a size on the pilot too.

[TRX250EXER]

its different for different exhaust. we are talking about e-series. But like I said, it might be different after I adjust my vavles. Ive only done that once since Ive had it and its way way over due. I think they may be ticking a little too. when my buddies 300ex valves were off his jetting was way off. he even borrowed jets from me(which he lost) to try to get it dialed in. he never did until he adjusted his vavles and then he shot way back up in jets again. back up where they should be. So a word of advice would be to do a vavle adjustment before you rejet. then you wont have the problems Ive had.

[RUFIO]

but im running no airbox lid, a white bros e-series, a twin air filter, and i never rejetted, and it runs great

Originally posted by TRX286
but im running no airbox lid, a white bros e-series, a twin air filter, and i never rejetted, and it runs great

If you rejet it will run even better,,,you can take that to the bank..:D

[TRX250EXER]

The only way I can see that it runs great is because of your lean jetting. sometimes when a engine is just a little lean, it will run crazy. and rev quicker. But it also runs hotter and causes damage to the engine. messes up vavles and can over heat it and seize it up. I bet you got some backfiring tho huh? once you get the e-series pipe tuned in just right it wont backfire anymore. Mine backfired forever until I finally got it dialed in.

[RUFIO]

it backfired like a mother, untill i took the airbox lid off, then it immediatly stoped

[RUFIO]

after i rejet, will I have to get my valves adjusted? how much will this cosT?

[TRX250EXER]

do it yourself its not that hard. all you need is a feeler gauge.
I think there is a walk through on here for a 400ex in the tech section. the 250ex will be different but that will get you an idea.

[Jay300ex]

Well if you are running with no airbox lid you probably should rejet, just because you are pulling in more air. I run a Eseries slip on and I didnt do anything to my airbox, so I didnt rejet, My plug is fine to the look of it ( light brown chocolate color? ) It doesnt backfire either , just gives little pops, once in a while when backpressure is kicking in ( usually after riding throttle pinned to hit a hill or jump ) . Oh and I wouldnt make your bet on making the 250ex manual, youd need a new engine =)

Jay