K&N jet kit

[rooster_20]

does anybody know what the K&N jet kit includes as in jet sizes and parts I have a Powerfilter and a White Bros-E series and was thinkin bout jettin it any input would help would the jet kit even speed me up at all?:huh

[UglyMotha™]

dunno what all the jets are but you'll use either two of the largest ones in the kit which is either a dj165 or a dj170 kit also includes a needle and a main jet adapter, your money would be better spent if you just stuck with khein jets I went back to khein jets a year ago and sold my k&n jet kit, didn't notice a bit of difference

[rooster_20]

Whats the price difference in the two and which one would be better for my application?

[rooster_20]

I just got some papers in from rockymountain (I was so excited to bolt the pipe on I lost them lol) white bros says the stock jet is 155 and with the pipe on and the air lid off they used a 165 main jet. I have zero experience with jettin but i was wonderin if I could just buy the 165 main jet instead of a whole kit?

[cals400ex]

the stock mainjet in a 400ex is a keihin 148. i would recommend a keihin 158 or so with a pipe, filter, and no air box lid. however, this could change quite a bit depending on the temperature you ride in and the elevation your at.

[rooster_20]

can i just buy the 158 jet instead of the whole kit? and does jetting it really help that much i mean would i tell a difference?

[400exrider707]

I ran a 155 keihin with those same mods and ran quite rich. But every machine is different. Also you can buy just the one jet or just get a couple and do some testing. They are anywhere from $4 to $8 a piece depending where you get them. Also you may not notice an improvement in power if you jet it but it is really bad for your engine if you dont. Putting on a pipe, filter and taking off the air box greatly increases the amount of air flowing in and out of the engine. Your engine needs a "perfect" mix of air and gas to run at peak performance. Increasing air and not increasing gas flow would be bad and could cause overheating and eventual engine failure. You need to increase the amount of gas flowing in the engine by jetting richer. Hope this helps.

[rooster_20]

thanks very helpful!

[rooster_20]

Hey I was lookin thru my ole dennis kirk book and found some keihin main jets. they have the 13 series is that the jets i am looking for? They are sold in packs of 5 and i was gonna buy the pack that included the 150-152-155-158-160 jets also i found some nice uni 1inch air vents that can pop right in my air box lid after drilling some holes does this sound like a good idea any opinions would be appreciated thanks:D

[cals400ex]

Originally posted by rooster_20
Hey I was lookin thru my ole dennis kirk book and found some keihin main jets. they have the 13 series is that the jets i am looking for? They are sold in packs of 5 and i was gonna buy the pack that included the 150-152-155-158-160 jets also i found some nice uni 1inch air vents that can pop right in my air box lid after drilling some holes does this sound like a good idea any opinions would be appreciated thanks:D


yes, you want 13 series keihin mainjets. you can get those uni vents. however, i would probably get the gt thunder velocity stack. i like that a bit more than the vents.

[rooster_20]

what is the thunder velocity stack and why is it better

[cals400ex]

you can see it at www.gtthunder.com

it is just a 2 inch tube that goes in your airbox lid. i am a big fan of air velocity, not necessarily volume. this tube should be stuck in the back of your air box lid so that way if it does suck in water, it will miss the air filter and go to the bottom of the air box. it is also cheaper than the a outerwear air box lid. it is up to you, but i have had both and i prefer the velocity stack.

[rooster_20]

not the whole lid that k7n makes i was talkin bout the little filters that are 1'' around you drill holes in your lid and place em in uni makes em. what do you think bout those?

[cals400ex]

Originally posted by rooster_20
not the whole lid that k7n makes i was talkin bout the little filters that are 1'' around you drill holes in your lid and place em in uni makes em. what do you think bout those?



i realized that when i replied the first time but i type so much on here i get confused sometimes. yes, i have had the outerwear air box lid, the six uni vents and the gt thunder velocity stack. i really couldn't tell if my bike was getting much more air with those vents. for the price i guess you can't beat them. i don't know. i would still place them in the back of your air box lid if you get them. i had one or two over the top of my filter and you could clearly tell where the vents were located because i would have little one inch dirt circles on my filter.

[Jonas]

All you need is a main jet. You can buy them at any Honda dealer. We sell them for $3.50 ea where I work. Don't bother drilling holes in you air box. You've got some good recommentations on jet size already.

[rooster_20]

thanks :D cant wait to order my jets and try them out!

[blakefoote]

my jetkitimproved my performance alot my 400ex was clockedat 85mph this weekend. And u c wat all i have on it.;)

[rooster_20]

what all have you done too it?