Jet size, airbox lid question

[JRN2786]

I have searched but cant find the info i need so hopefully someone can help me.
I have a 01 400ex, wont idle and dont like to start when its cold. has a Pro Cuircut slip on and uni filter with lid on . Tool the carb off to see what jets and its a 155 main and 38 pilot. Seems close right? Do you think it may be better with airbox lid off with these jets? i havent checked the plug yet. If the jets are about right then what do i need to do to make it start easy. Thanks

[PLF]

42 pilot would help

[honda400ex2003]

the 42 should help or you could go to 3.5 turns out on the f/a and see how it does then.

I guess you could probably take the lid off for the summer but i would leave it on for the winter months or under 40 degrees.

a 150 or 152 is usually good with a filter and slipon so you will have a bit of a margin to open the lid up in the summer.

steve

[JRN2786]

ok, i got it idling and running pretty good but when its idling and i give it full throttle fast it will die or almost die. Is this due to pilot being to small?

[honda400ex2003]

not usually, it seems that usually it is from the main jet being a bit rich. just my experiences though. how does the plug look? do some plug chops and see how it looks after changing it to a new one.

steve

[JRN2786]

I forgot to say that I have uni filter and supposed to have a hotcams stage 2 in it but idk I will do a plug chop and see. I took the airbox lid off and it acts the same way.

[JRN2786]

Went to do plug chop today and found out I need a thin wall socket which I don't have I will pick on up this week. Anyhow it won't idle till it warms up and then webmaster I adjust idle it either idle to high or it dies. So I'm guessing the jets are wrong or any input on this? I don't know where to start. Seems like it should be pretty close to being right but its not.

[honda400ex2003]

depending on what pilot you are going to run 2.5-3.5 turns out (42-40-38) go to a 150 and see how it runs with the lid on.

if it wont idle you have a pilot problem

when it dies out from revving you have an issue with your main jet being too big.


i ran a 150, needle on the 3rd notch, and 3.5 turns out all the time for quite a few years with my t-4 and k&n setup. change the plug, that may help it out also since the one thats in there could be fouled up pretty bad. you will have to wait to do that though as you said.

in the mean time throw a 150 in there and see how it runs. along with going out on the f/a to see if you can get it running better after it is warm. get it running and take it for a 10 minute ride if you can. then start to adjust the f/a since it will be warmed up fully by that time. you cant adjust stuff with the engine slightly cold, you will never get anywhere with it if you do that.

http://s759.photobucket.com/albums/xx239/rocky_mtn_honda/TRX400EX%20Manual%20Pages/?action=view&current=carbadjustment.jpg

that is the proper procedure to adjust the f/a screw. you dont need a tach, you can get it close enough without one just by listening to it. also give it some gas inbetween each change and let it settle down again before doing another change. you have to give it time to adjust.



steve

[JRN2786]

Thank you very much I will pick up some jets while I'm out next week BTW I just got it back from the dealer and it has a new plug in it they wanted 200 bucks to do the netting and clean the carbon so I opted to do myself bad thing is that means the plug isn't part of the issue I will try the f/a screw first. Thanks again

[honda400ex2003]

no problem, report back the results. steve

[JRN2786]

I'm gonna get a 150 and 152 main jet what size pilots should I get? Just a 40 or should I get the 42 also? I'm guessing the 45 will be to big right

[honda400ex2003]

imo get the 40 if you dont plan to go any bigger than a 400cc. if you do get both of them, it never hurts to have extras around for future mods anyway.

i will recommend starting with the 40 at 2.5 turns out on the f/a screw and the 150 and see how it goes for you.

did you do any adjusting on the f/a today to see if you could get it to idle after it was warmed up? you may not need a pilot jet if you can get it dialed in without going over 3.5 turns on the f/a screw. you could save yourself some money, pilots arent cheap lol.

expect to have 25 bucks worth of jets or so with 2 mains and 2 pilots. :O anything less than that is a bonus. :D
steve

[JRN2786]

No couldn't adjust f/a screw cause I don't have a screwdriver that will fit. But I'm getting bored so im goin to try a flat head bit and a rachet wrench... what is stock position on the fuel screw?

[honda400ex2003]

lol been there done that. lol if anything loosen the clamps and give it a turn while still in the boots. it is quicker than jacking with that stupid screw with it straight up and down most of the time. lol i get so irritated sometimes with that screw. its hard to believe something like a simple flat head screw can be such a problem.

:rolleyes: :eek2:

steve

[JRN2786]

Ok tried the screw at 2.5 turns and it didn't like it at 3.5 it was better but the idle is hanging when I let off so I'm guessing pilot is to small or main is to big?

[honda400ex2003]

did you make sure you gave it some gas and such to make sure it was smoothed out a bit?

bigger pilot would be in order since it is still too lean imo. esp if it is hanging after blipping the throttle and letting it sit for a couple of seconds.

steve

[JRN2786]

so hanging idle is a sign of being to lean? Yeah I rev'd it thougholy and let it settle for a good amount of time. It took way to long to get back down to the idle speed so I guess ill start with a larger pilot probably a 42. For 5 dollars and 30 minutes of work its as good a place as any to start. BTW my idle screw is almost out of adjustment and its idling about right is that normal? Don't remember if I said but my needle is on the 3rd notch I tried it on the fourth down and that wasn't a good idea. Thanks for the assistance.

[honda400ex2003]

i would start with the 42 and go from there at about 2.5 turns out then.

usually a hanging idle is a sign of a lean condition on the pilot in my experiences.

the 4th notch will richen up the mid range also. going to the second would lean it out. at least you learned where the needle starts to take effect on the throttle haha cause it almost died when you hit that spot haha.

3rd is good for what you have going on.

we will get you all set up sooner or later. lol get the jets first then you can play from there one step at a time. dont do everything at once.

steve

[JRN2786]

Yeah it is all wrong now hopefully i can get it straitend up ill post what happens with 42 pilot

[honda400ex2003]

so the game plan is

152, 42, 2.5 turns out and see how it goes. you may be able to put the 150 in there but the 152 will be good if you are below 1000 ft or so. 1 jet size wont make a real big difference anyway. lol

steve

[JRN2786]

Right 42 and 152 at 2.5 turns to start with and I'm pretty close to sea level I think for sure less than 1000 ft above

[honda400ex2003]

i think you will be good to go with that :D steve