jet kit

[BranMan]

i bought a dynojets jet kit for my 400ex and installed it by the way the paper said but im kinda wondering if it is jetted right..... the jet size that they tell u to use, is it usually the right 1 or wat i though u had to mess with it a little bit... anyway if any1 has used this kit let me no wat u think.... thanks

[danlt73]

i think if you follow the directions, you might have jetted it rich, i think its like that with all the dynojet kits, but dont quote me on that

what dynojet fails to mention is that their kit is just a get you close to correct jetting kit...two same modle bikes runnning the same filter/exhaust setup may actually require different jetting so dynojet can be close, but not always 100% correct...

[BranMan]

well ok then if some1 has the kit can u tell me wat size jets u use i have a k&n filter exhaust and no air box so if some1 can tell me wat to use to get closer that would b great

jetting is essentially a trial and error process. there is not one set jet. for instance. my friend and i both have 06 trx 450r's if running the same set-up(same aftermarket filter, lid off, baffle out) he may need a 170 main jet while i may need a 165...

ultimately, you will have to do plug reads to see that you are not too lean or too rich...if you need to go one way or the other, go towards the rich side as lean is really bad for the motor. the dj kit settings will be a good starting point for trial and error

[BranMan]

well thanks for all the help.. i bought the kit and i didnt no wat it would b like and i should have bought a k&n jet kit but owell... thanks again

the k&n jet kit is just a rebranded dynojet kit.

look here for some info on jetting...

jets-r-us (http://www.jetsrus.com/main_page.htm)

click on the faq-jets and jetting for some good background info and then on faq reading plugs to help you out with dialing in your jetting...

[450ERRRRRR!]

Junk the jet kit and buy Genuine Kelihn jets from your dealer.:eek2:

Originally posted by 450ERRRRRR!
Junk the jet kit and buy Genuine Kelihn jets from your dealer.:eek2:

that is my feelings too, but he already has the kit and probably don't want to get rid of it now so i was trying to lead him in the right direction. hopefully i helped.

[BranMan]

yeah i no that is wat i should have done but i have the kit already and i want to try and see if i can make it work... but thanks for all the help

did you read the 2 faqs that i suggested? those will help you out alot with understanding exactly what you are doing and how to go about getting your jetting as close as you can without using a dyno.

i am/was in the same boat with my 400ex. the previous owner had it close using a dynojet/k&N jet kit. i got it knowing it was a little off. he knew it was a little off too. it took me a few hours to get it right. 400ex's are a little hard to dial in, my 300ex was much easier...gonna just by a few stock jets for the 450r when i do it soon...