rejetting question

[Honda_exrider]

how do you rejet a 300ex. what is the point in doing it. i have a stock pipe and a k&n air filter. should i do this, and how does it help?

[whiteflash]

Originally posted by Honda_exrider
how do you rejet a 300ex. what is the point in doing it. i have a stock pipe and a k&n air filter. should i do this, and how does it help?

You may want to do a search...but i'll do my best to give you a summary. Usually when someone rejets, they are rejeting for a pipe, filter, or removing airbox lid, etc. All of these parts allow more air than fuel into the engine, in doing this, the air-to-fuel ratio gets messed up. In order to get the air-to-fuel ratio back to normal you need to get more fuel. installing bigger jets, like a main jet, into your carbuerator allows for more fuel. Now thers usually more to it than that, you got your pilot jet, air-fuel screw, and some other componets to jetting that i dont fully understand so i cant tell you.

You most likely will need to rejet with a aftermaket pipe, but as long as you have your stock pipe and keep your airbox lid on you shouldnt have to rejet. Now you could ditch the lid and rejet to get some more power.

Too much air is called LEAN

Too much fuel is called RICH

if you spark plug is white then it is lean, black is Rich. You should shoot for a brownish plug.

Correct me if im wrong on any of this....

[prepracing]

Originally posted by whiteflash
You may want to do a search...but i'll do my best to give you a summary. Usually when someone rejets, they are rejeting for a pipe, filter, or removing airbox lid, etc. All of these parts allow more air than fuel into the engine, in doing this, the air-to-fuel ratio gets messed up. In order to get the air-to-fuel ratio back to normal you need to get more fuel. installing bigger jets, like a main jet, into your carbuerator allows for more fuel. Now thers usually more to it than that, you got your pilot jet, air-fuel screw, and some other componets to jetting that i dont fully understand so i cant tell you.

You most likely will need to rejet with a aftermaket pipe, but as long as you have your stock pipe and keep your airbox lid on you shouldnt have to rejet. Now you could ditch the lid and rejet to get some more power.

Too much air is called LEAN

Too much fuel is called RICH

if you spark plug is white then it is lean, black is Rich. You should shoot for a brownish plug.

Correct me if im wrong on any of this....

Sounds like you explained it pretty well.... and to add to it why you should rejet it....... run one lean for to long and you will be replacing some burnt valves, piston/rings from it running to HOT

[Honda_exrider]

thanxs for the info but will i have to rejet for an air filter and is it a bad idea to remove the lid if i ride through dusty places and a little wet and a little muddy? and how do you even go about doin it, do i have to buy a kit and is it hard to do? PLEASE GOD SOMEONE HELP ME!

[whiteflash]

Originally posted by Honda_exrider
thanxs for the info but will i have to rejet for an air filter and is it a bad idea to remove the lid if i ride through dusty places and a little wet and a little muddy? and how do you even go about doin it, do i have to buy a kit and is it hard to do? PLEASE GOD SOMEONE HELP ME!

you shouldnt have to rejet with just a filter and the lid on, but, when you remove the airbox lid it allows for more air into the carb, so then you probably would. I have my lid off, and i ride in close to the same conditions as you and i'm fine, but you would need an outerwears cover for your K&N most likely. Or, you could buy an EHS racing lid, it is a filtered airbox lid that allows for the same amount of airflow as no lid, but it filters water, mud, etc. I had one and it worked great! check them out at www.ehsracing.com

how do you even go about doin it, do i have to buy a kit and is it hard to do?

you could buy a jet kit, or buy the individual jets at the dealer. A jet kit would probably be alot easier for you cause it sounds like its your first time. Or, you could take it to a ATV shop and have them do it, but i would wait until you get a pipe to take it in. I took my quad to the dealer to rejet mine because i wasnt sure about it and didnt want to screw anything up.

[Honda_exrider]

do you think this is a good idea and do you think i'll have to rejet for it

[whiteflash]

Originally posted by Honda_exrider
do you think this is a good idea and do you think i'll have to rejet for it

personally, i wouldnt get it, i'd get something better and cleaner looking like the ehs lid. but you'll need to rejet if you get it.

[Honda_exrider]

but how do i go about doing it will i have buy a kit, i mean what are steps(this is my first time doing this). will i be able to see an increase in power?

[whiteflash]

Originally posted by Honda_exrider
but how do i go about doing it will i have buy a kit, i mean what are steps(this is my first time doing this). will i be able to see an increase in power?

a jet kit or the airbox kit? explain more....

[Honda_exrider]

sorry... a jet kit, i read the article on here about it but i still don't fully understand it.

[wboy62417]

personally i would get a pipe before you go all out on the air box find you a white brothers pipe or something and then you can deside if you want to take the lid off (you will have to clean it alot) i wouldnt take the lid off without having a pipe that is like buying a cd without a cd player to play it in you wont see a big diff. in power till you get a pipe

But if you insist on taking the lid off and rejeting i would buy a repair manual and a jet kit (since its your first time) and do it yourself it isnt too hard if you know how to use a screwdriver