Hardstart poor idle

[CTC B4Z]

Im not sure if its just the cold, but the bike is stored in my heated garage, but everytime I go to start it, it takes quite a few cranks. also, it will fire up, run, than die out. It'll only stay running on its own after I hold the throttle for awhile or roll around in 1st gear. otherwise it will just die out... any suggestions?

[schjimz]

mine did the same thing...i added a new head gaskit

[Miami_Vice454]

its just cold, mine does the same. we need to go up one size on the pilot jet.

[honda400ex2003]

unfortunely that would not be the first option when looking into a hard idle. I would inspect the gasket maybe and see if it is leaking but other than that, here are some questions to answer first.
1. does it normally run this way in all conditions? you said it was doing it in the cold but it is in the garage but does it do it in the summer also when in the garage?

2. is there any performance upgrades done to it? i did not get a chance to see your sig to see if anything was done so my appologies if they are there.

3. is the air filter cleaned?

4. is the battery charged fully or has it been sitting for a month or two or even longer?

5. is it new gas in it or older like 3 months or more?

I would suggest trying a few different things to help to see if it helps this first. make sure the battery is fully charged first to make sure it is getting a good turnover. then try to pump the throttle twice before trying to start it for the first time. if this helps to get it running a bit faster, i would suggest turning your fuel/air screw out 1/4 turn to help richen up the pilot circuit for the winter. If it doesnt help, you may have some other issues. the gas could be getting a bit old, or you could have something clogging the pilot circuit a bit causing it to run rough. steve

[honda400ex2003]

oh and welcome to the site! steve:D

[CTC B4Z]

I have only owned it in the winter, so summer conditions, I cannot verify... But after riding, it is good except sometimes when I goose it, it will bog down for a split second, but it will pick right up.

The quad has a Big Gun exhaust, but it was said to be jetted properly.

Air filter is a K&N and yes its clean.

Battery is perfect.

New 93 octane gas. I am now however going to run some BBK 44K through it.

Which adjustment screw idle and which one is mixture?

[honda400ex2003]

it is located on the bottom of the carb on the intake side. i guess you could try to turn it out a bit and see if it helps. otherwise you could try a 40 pilot to help with the cold starting. steve

[CTC B4Z]

ok. its sitting in the extremely warm shop right now. I got it in pieces putting new carrier bearings n chain on it. Ill start it up tomorrow, see if it holds idle. if it does, its just the weather...

[CTC B4Z]

Also when cold, if I go WOT it will die. not in gear, just sitting

[honda400ex2003]

it may be a bit lean cause of the cold causing it to die out from not having enough gas at the moment the throttle is hit. i think with a small turn on the f/a you should be ok but it is really hard to tell without being there. lol. steve

[CTC B4Z]

I hear ya man. Im a diesel mechanic and on the phone/online diagnostics is HARD stuff...


but I appreciate it, thanks!

[honda400ex2003]

no prob good luck. the f/a is a flat head screw that is brass. it is just behind the starter on the carb. i will look for a pic to show you. steve

[honda400ex2003]

the f/a is on the motor side i guess, it is set 6 in the diagram. steve
http://www.bikebandit.com/houseofmotorcycles/2003-honda-motorcycle-trx400ex-fourtrax-ex-carburetor/o/m2661sch98410

[CTC B4Z]

thanks man!

[CTC B4Z]

I adjusted the screw today, no change... I want to rebuild the carb. I believe I want a 58 Pilot and 148 main??? Where do I get jets?

[Wr3sTl3b0y]

if you havn't run it in a while their could be moisture in your tank i know after a few months mine got water in it even in a heated garage i didnt put stabalizer in it or fill it full before storage

[honda400ex2003]

38 pilot, 148 main, rd clip position on the needle, and 2.25 turns out on the f/a is stock. you can get jets either at a yamaha or honda shop, if you bring the jets with you, or you can go to jetsrus.com and get them. It may just need a good rebuild and it will be good to go again. Otherwise is anything done to it modification wise or anything? steve

[CTC B4Z]

no aftermarket besides the K&N and Big Gun. I was told the carb was jetted, but I do not believe this since it runs like this. Even sitting in the shop over the weekend, warm, it wouldnt hold idle.


The jets I pull out, will they have numbers on them? I have not dealt with jets since my Blaster and do not remember at all

[CTC B4Z]

what does rd clip on the needle mean?


haha, sorry, I am such a newb to this quad

[honda400ex2003]

Originally posted by CTC B4Z
what does rd clip on the needle mean?


haha, sorry, I am such a newb to this quad

sorry about that it should be 3rd. lol it is from the top of the needle. there are different slots on the top of the needle to adjust it on the 04 and less models. steve

[honda400ex2003]

Originally posted by CTC B4Z
no aftermarket besides the K&N and Big Gun. I was told the carb was jetted, but I do not believe this since it runs like this. Even sitting in the shop over the weekend, warm, it wouldnt hold idle.


The jets I pull out, will they have numbers on them? I have not dealt with jets since my Blaster and do not remember at all
also there will be a number on them to indentify the jets. I would say that you should be right around a 152 main jet or a 155 main jet when you take it apart depending on if it is a full exhaust or slip on. steve

[CTC B4Z]

thats even if im jetted.


factory if 38 and 148, correct?


if so, I'd want a 42 and 158 right?

[CTC B4Z]

http://atv.off-road.com/atv/article/articleDetail.jsp?id=190593


that also says to raise the needle one notch. I suppose that is the 3rd clip your talking about

[honda400ex2003]

yeah that is what i am talking about. you could also try to put a 40 pilot in it to see if that would help it run a bit better. it is most likely too lean right now with the 38 so you may want to bump it up to a 40 or 42 like said in the article. How does your plug look?

factory if 38 and 148, correct? this is stock setup


if so, I'd want a 42 and 158 right? this is what you may be at. it depends on what the person before you put in it. you could definitely start with that and see how it runs. I would say that a 158 may be a bit rich depending on where you are at but if you are close to sea level you will probably be ok running that. how much did you turn the f/a screw. you could possibly try to go out to 3-3.5 turns and see if it helps before you start to buy jets. the first thing you should do though is take it apart and see what jets are in it and where everything is set. steve

[CTC B4Z]

I turned it 1 turn out today. I'll take it apart tomorrow

[honda400ex2003]

it probably has a stock pilot then, i would go up to a 42 and see if it helps it out. steve

[CTC B4Z]

thanks man. appreciate it. I'll be back tomorrow with the verdict

[honda400ex2003]

sounds good, find out what is all in it first off. lol. then you can go from there. steve

[CTC B4Z]

Sure enough, stock jets... I found a 38 and a 142. So I ordered a 42 and a 148 I believe

[honda400ex2003]

was the 142 round with an adaptor looking thing screwed into it. the 148 is the stock side. I think the 142 is a dyno jet. so you should be pretty close with that. steve

[honda400ex2003]

it could get ugly now if you already bought the jets. lol. what were your mods again. A full exhaust or slip on big gun? to go along with the k&n. steve

[CTC B4Z]

I really dont remember... Ill grab a pic tomorrow.. and I think I order the 158 on the main...

[CTC B4Z]

I think its a full exhuast big gun and K&N

[honda400ex2003]

thank goodness for that. lol. take a pic of the jet you have in it now. i bet it is a dyno jet. you would probably be good with that for sure. with my t-4 slip on and a k&n i was running a 138 dj with the needle on the 3rd clip position, 38 pilot, and 3.5 turns out on the f/a. I would suspect that the 42 will be a good thing for the colder thinner air since it may be running a bit lean idling. steve

[CTC B4Z]

post back tomorrow!!!

[honda400ex2003]

alright sounds good. steve

[CTC B4Z]

forgot camera again... it just looks stock, nothing special I dont think... I got my bearings n chain in today, jets should arrive tomorrow... Ill keep posted. thanks

[CTC B4Z]

went to rebuild carb today and some black rubber ribbed thing fell out.. no idea where it goes... the kit i got has a new one... HELP

[honda400ex2003]

this is a full schematic of the carb. How big is it and such, take a pic of it. It may have come out of the accelerator pump if it is round with 3 tabs. it is a diaphram inside it. that wasnt a very good desciption of a ribbed thing lol. steve

[CTC B4Z]

ok, stay here. im going to get a pic... lol

[CTC B4Z]

yes it has 3 ribs on it with a wider opening at one end...

[CTC B4Z]

I have looked on bikebandits... but cannot find the thing in the schematic

[CTC B4Z]

http://i286.photobucket.com/albums/ll82/CTC_B4Z/400EX/400ex007.jpg

[honda400ex2003]

it goes inbetween your bowl and your shaft for the accelerator pump. it goes through the body to help seal it off. so whey you take the bowl off it will go on the shaft of the accelerator pump when you put it back on. steve

[honda400ex2003]

http://www.bikebandit.com/houseofmotorcycles/2003-honda-motorcycle-trx400ex-fourtrax-ex-carburetor/o/m2661sch98410

so it goes on the outside of the bowl on the number 9 shaft when it goes back together. i hope this helps. it goes inside the big black cover through the hole at the bottom that the accelerator pump goes through to go up to where it meets the lever to push it. lol steve

[CTC B4Z]

sounds good... update tomorrow.. I got a 42 jet and a 148(they ordered the wrong one, great)

[CTC B4Z]

The new jet I got doesnt look anything like the one that was in there before I took it apart. This is the 158 I just installed today. But the jet I removed was probably 1/4 of the length, had a slot in it for a flathead, and had the number '42' on it... I'm so confused.. Did someone put the wrong type of jet in it before?... Even with the 40 and 158 installed, when i blip the throttle itll die... but it idles a bit better... 3 turns out on FA

[honda400ex2003]

take some pictures of it. I bet it is a dynojet one. steve

[CTC B4Z]

no prob. I would be riding it now, but the chain i got was too long.. I dont understand. I ordered a chain and sprocket kit a 99 400ex, but the chain is like 8 links too long... any idea what size chain i need?

[honda400ex2003]

it is 94 links. lol. steve

[CTC B4Z]

thanks man

[honda400ex2003]

no prob glad to help. steve

[CTC B4Z]

http://i286.photobucket.com/albums/ll82/CTC_B4Z/400EX/jets23.jpg

[honda400ex2003]

it looks like a dynojet type one, it may in fact be a fmf one but they are the same with different markings possibly. it was a 142 dj. Did it happen to have dj 42 on the top of the round one? I think the dyno jet ones say 142 dj on them. the fmf ones may not, they may just have 42 on them. also it should have had a hex type thing that it screwed into when you took it out along with another brass fitting that the hex one went into. the brass one that the round one screwed into has to come out before the new jet can go in. it will not fit back together with both in. You should take a pic of that too and i can make sure you have it all in right before you put it back together. steve

[CTC B4Z]

this is what i have now....

http://i286.photobucket.com/albums/ll82/CTC_B4Z/400EX/jet.jpg

[CTC B4Z]

its runs alot better now and finally idles, but if i blip the throttle WOT it will try to die

[honda400ex2003]

that is the new jet right. that is correct. It may be a bit rich on the main then. Is that a 162 or a 160? what you want to do is warm it up fully, then see how it runs. change the plug, take it for a good 10 minute ride or so and check it again. steve

[CTC B4Z]

ill turn her in 3/4 of a turn, ride it and see if she bogs at all.

[CTC B4Z]

yes thats the new jet... Im now running a 58 and a 142

[honda400ex2003]

whoa wait a second, i think something is mixed up. you may want to check that again. maybe a 38 and a 162. make sure the main is screwed in all the way too :eek2: I am not really sure what you are going to turn in, if it idles good then leave the pilot alone, leave the f/a screw alone and work with the main first. i think you may need to go to a 160 main and you will be set. steve

[CTC B4Z]

damnit i keep on confusing this...


im running a 158 and and 42!!!


sorry

[honda400ex2003]

sounds like you should be pretty close then. warm it up and see how the plug looks. it is only doing it at wide open huh? steve

[CTC B4Z]

I have yet to ride it. I'm just idling it and revving it in the shop. So in nuetral if I WOT REAL quick, it will stumble.. Havent tried it in gear yet however. but before I changed the jets even, it wouldnt idle at all and under load it would bog... I should be riding itthis weekend

[CTC B4Z]

oh, and yea i did raise the needle one clip... I now have 3 exposed at the top..

[honda400ex2003]

sounds good you may have to raise your needle to the second clip and you might be good to go if the plug is good. what you should do when you go ride it is plug chop it. heres the methods to do it. you can perform this at any position of the throttle, you just have to have a bunch of new plugs to do it a bunch of times. steve

plug chopping
the plug chop is an essential step in setting up jetting. not only does it help you get good performance, but more importantly, it helps you make sure yr bike is not running so lean that it will blow up!

1. wind it out! . warm the bike up well (5-10 min) with a new or fairly clean plug, correctly gapped, then wind the bike out in a gear. generally, i like to do this in 3d, but it depends how fast yr bike goes in each gear and where y'r doing this test (trying to run a bike out in 4th is not advisable in, say, a school zone). at least get into 2d.

2. hold it there ... even though you will be nervous, hold it in gear at max rpm for a while... what you are trying to do here is simulate the hardest use the bike will ever conceivably see. if you jet for the most stressful conditions, then yr normal use will be well within safe margins. keep yr hand on the clutch, as you could (doubt it, though) seize if you are jetted too lean to begin with. as always, use yr own judgment!

3. kill it. simultaneously hit the kill switch and pull in the clutch. hitting the kill stops the plug sparking; pulling the clutch stops the clutch from turning the engine over (bringing in more unburnt fuel). thus, you get a perfect picture of what the sparkplug looks like at the moment you hit the kill switch.

4. pull over, pull the plug out you will want to have gloves or a set of pliers, cause the plug will be fking hot!!!

5. read the plug. if the plug is:

black and wet: yr jetting is too rich

chocolate brown: yr jetting is right on! you kick ***!

white and burnt smelling: yr jetting is too lean! upjet now . you might also notice a blistered insulator. this is real bad. you are lucky you haven't hurt yr bike worse!

[honda400ex2003]

Originally posted by CTC B4Z
oh, and yea i did raise the needle one clip... I now have 3 exposed at the top..

go back to the 3rd from the top. this will help to lean it out a bit. even second from the top may be better this will lean it out a bit more depending on how your plug looks. the higher up on the needle it is the leaner it makes it. the lower the richer. this is with the needle pointing down. steve

[CTC B4Z]

awesome.. what gap am I looking for and what kind of plug?

[honda400ex2003]

dpr8z and i think around .030" is about right. i dont really do them, they come pregapped so you should be ok. steve

[honda400ex2003]

http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=DPR8Z&store=&catId=&productId=pDPR8Z&leafCatId=&mmyId=

heres the plug. it isnt special though. lol the cold plug is dpr9z for hotter weather but you shouldnt need it. just a bit of frivilous knowledge for you. lol. steve

[CTC B4Z]

when you are hitting the kill switch and pulllin clutch in, are you off the throttle or still on???

[honda400ex2003]

still on i suppose it is really all done at the same time. let off the gas, kill it, and pull in the clutch simultaneously. lol steve

[CTC B4Z]

its going to take me like 15 trys to get it right... lol thanks man.

[honda400ex2003]

it should be really close with a 158, 3rd needle postion, 42 pilot, and 2-2.5 turns out on the f/a screw. you shouldnt even have to mess with it anymore once you check the plug for the first time. it may need a 160 but most likely not. steve