EX Tech

[Holty]

In the EX Tech section of this website, there is a carb jetting section. "Part I" is up and is very helpful, but does anyone know when "Parts II & III" will be posted. I'm having constant jetting problems that I just can't seem to get right. This has been going on now for months and I need help bad! Thanks.

[4punksdad]

explain problem............maybe we can help?

[Leo]

as I type this I'm working on the backer for the woodstove.. using the 'fake' rocks..

(I hate masonary work!!)

anyway, it is the LAST bit of inside work and the house is done. Nothing left but some minor landscaping this spring :)

look for major site updates right after x-mas.

Leo

[Wheelie]

What jets are you currently running? I'm sure someone on this site can help you out.

[Holty]

I'm using Dyno-jet #170 for my main. I'm back to the stock needle and stock needle location, and I'm not sure what pilot jet is in there. My mechanic was doing the jetting for me. Also, i have no air box lid on and using k&n filter.

On the bottom end the bike is sluggish and mid and top is dosn't have the power is should. I still think with the main i'm running too lean. I just don't know anymore. I'm ready to throw it out the window.


Anyway, the point of my post is I want to start all over again and was hoping for a good reference point to read and follow directions when working on the bike. thanks for all your help.

Leo, keep up the good work, this site is great!

[4punksdad]

so you have opened up the air & fuel & not the exhaust?
with my set up @ around 500' elevation I am still running a little rich.

modified stock exhaust
drilled/removed airbox lid
stock air filter
stock jetting except for 165 main.

hope this helps.

[Holty]

i have a white bros. slip on.

[400MXer]

I have a 165 in mine. I live in michigan and have a Duncan exhaust, No airbox lid, K&N Filter and that's it. My plug is the perfect color. But you say that your running a 170 and your still to lean....hmm. Trial and Error. just keep trying jet sizes untill you get it right.


It's all about the Trial and Error!!!!

[Taco]

Originally posted by Holty
I'm using Dyno-jet #170 for my main. I'm back to the stock needle and stock needle location, and I'm not sure what pilot jet is in there. My mechanic was doing the jetting for me. Also, i have no air box lid on and using k&n filter.

On the bottom end the bike is sluggish and mid and top is dosn't have the power is should. I still think with the main i'm running too lean. I just don't know anymore. I'm ready to throw it out the window.


Anyway, the point of my post is I want to start all over again and was hoping for a good reference point to read and follow directions when working on the bike. thanks for all your help.

Leo, keep up the good work, this site is great!

wait a minute let me get this straight you are using dynojet jets with your stock keihln needle??? I believe that is a source of problem they are supposed to be used together. Dynojet jets meter fuel differently than keihln jets (ie. different taper etc.) I would reinstall the dynojet needle and follow the dynojet instructions most i have seen run I believe the 165 dynojet.

[Holty]

thanks, i'll give that a try. what slot on the needle should i put the e clip? also, what pilot jet are you guys running for 3000 feet and under? thanks alot!

[Taco]

Im not sure what clip you need to put the clip on the dynojet needle i would just read the instructions that came with the kit if not im sure someone here could tell you where it goes. As for the pilot jet most people go to either a 40 or 42 pilot jet. It seems most go for a 40 tho so i would try that.

and make sure to let the bike warm up before making any changes,,,very important.

[stevengates45]

when i was messin with a smoothebored carb i spent gobbs of money with jets. turns out the jetting i had when i first put it on was right, the problem was my coil. this is just off the wall though, dont go checkin ur coil.

[Holty]

O.k., I just talked to my mechanic and found out for sure what i'm running right now. He said he put in the Dyno-jet 165 main, Dyno-jet needle in the 3rd clip position, and a 38 pilot jet. It seems to be running pretty good now with no air box lid except for a little low end hesitation???, but i plan on putting the outerwears air box cover on this weekend. will this effect it any? I wouldn't think since it is basicly still an open air box right? anyway, thanks for the help.

[400MXer]

There's still hesitation? Does it hesitate when it cold, or when it's warmed up too?

[MOFO]

If you require the mainjet to be a 165 and moved the clip on the needle, your pilot should be changed as well. Start with a 40 pilot jet....



Eric

[Holty]

When it is warm. The hesitation is a low rpm though. Maybe it's just me?? I don't know? Does that jet setup sound right to everyone? Maybe I just need to get my 14t on and see if that helps. thanks again for all your help. this site rules!

[MOFO]

Well, like I said...go with a bigger pilot. The pilot (aka slow jet) controls the first part of your RPM range (0-1/8 throttle). Also keep in mind your air/fuel mixture screw effects this range as well....sounds like this is where your problem is.


Eric

[ATVer14]

Does anyone know where the air screw on a 300EX is at? Also, what does the air screw control. I'm trying to get my jetting right for my new pipe, and I was just wondering where the air screw was. Thanks.
-Kenny

[QuadRacer041]

i would move the needle clip to the fourth notch down.