question about 300ex carb

[mackspeed]

ok, there is just waaaay too much to learn about this thing, i have searched other threads but im still not getting it. words like float plunger and jetting and this and that.

the engine is STOCk is there any reason i would have to REJET the damn thing? i just want to adjust a few screws and that be it.

is there a diagram someone can point me to so i know what each thing does?

i really wanna know what these 2 screws does, one is on a horizontal plane and it is just above one of the hoses that comes off the carb, it is tightened all the way, when i loosen it fuel comes pouring out of the carb!

the second is the one on the bottom that i cant really get to unless i remove the carb, is that the fuel idle screw? how far do you have to turn it to be bottomed out? it seems like everytime i think its at the bottom i can move it a little more. how far should i screw it out once i get to the bottom?

thanks for your time in advance, i have tried doing searches, but most posts and replies are filled with all sorts of terms i dont understand.

['03'300ex'er]

the first screw is the carb drain and the other is pilot jet screw book says 2 1/4 turns out, the idle adj. on mine is on a bracket that comes out below the carb but it has a cable that connects to carb

and yes i rejetted my carb and my bike was new it helps it alot when you get it done right.

[beak7707]

You should not have to rejet the carb if nothing has been changed from stock. Unless you have a pipe or filter there would be no reason it would run on stock jetting. The screw that leaks fuel is the bowl drain. On the bottom side of the carb there is a little screw that is the air/fuel screw, I would make sure it is set at 2 1/4 turns out. ALso DO NOT over tighten it just snug it up the turn it out 2 1/4 times. I honestly think your problem is a dirty carb, you need clean the bowl and jets. I would bet your jets are plugged up if it has set as long as you claim.

['03'300ex'er]

pmed you some pics of the carb from a repair manual check em out and see if that helps ya:D

[mackspeed]

thanks alot for the help guys, ill try those things when i get home tonight.

[mackspeed]

typically if the jets are clogged up will the carb run rich or lean? i think it is running too rich right now..

i took the hose that goes to the airfilter off while i was adjusting it and there was a heavy mist of fuel coming of the carb while the engine was running at wide open throttle.. is this normal?

['03'300ex'er]

before you try anything you need to do what beak said and clean the carb. your jets must be CLEAN before anything is gonna work right.