how to get the carb. out???? 400ex

[trx400ex07rider]

I'm trying to get my carb out of my 07 400ex, so far there is no straight answer on how to do it, i'm in the process of rejtting it but 1st of all i need to know how to get the carb out!!!!! please someone give me a straight forward answer

[honda400ex2003]

you will want to take the fenders off, then take the air box out by undoing the clamps. the tank should come off, then just unscrew the front clamp to get it loose. to get it off the machine, take the black over off on the right side and move the arm to get the cable off of it. unscrew the cable out of the carb by spinning the carb around then you can do what you need with the bowl off or by taking the bottom nut and cover off for the main jet if that is all you need. to get to the pilot the bowl has to come off then it is in a cylinder looking part on one side of the floats. to get the needle you have to take the top triangular part off and the two brass screws come out lifting the arm off of it. then the slider comes out and the needle is inside it. once jetted put it all back together, it shouldnt take more than an hour to get it all done. steve

[trx400ex07rider]

thanks a ton! that answers my question perfectly, i'm gonna do it all tomorrow, im doing a stage 2 by taking the air lid off. what other mods would you suggest for more power? preferably on the cheap side

[honda400ex2003]

other than a filter to go with opening up the lid that is about it. a coil would maybe help alittle bit along with a sparks racing timing advance key would be a couple of options for cheaper power. other than that a stage 1 hotcam would probably go nicely with the full exhaust. the cam is about 180. the coil is about 70 i think and the key is about 40 bucks total for it. that is probably the biggest bang for the buck power upgrade besides a cam. steve

[honda400ex2003]

also make sure you get the jetting dialed for the best performance. just doing the stage 2 recommendations may not be the best for the best performace. steve

[honda400ex2003]

you should be right around a 148 dj main with all of that. that is with a filter might i add. what are you at now with the full exhaust, a 142 or so? I used to use djs before i did my 416. steve

[trx400ex07rider]

Sweet. What is a hot cam? and the coil? i understand how to do all the jetting, thats easy but getting to the carb is the hard part. I'm running a 142 dj right now Lance

[honda400ex2003]

with a filter and an open air box you will be right around a 148-150 dj then, with about 3 turns out on the fuel/air screw, and the 3rd clip position on the needle. this is most likely wherre you are at now with just a 142 in it for the full exhaust without a filter according to the directions. a hot cam is a high performance cam for the 400. there are 3 stages ranging in different grinds and such for longer durations and things like that. stage 1 is a mild cam and it goes up from there. a coil controls the spark to the plug. the one i am referring to is called a monster coil made by amr. look both of them up on ebay and you will be able to see what they look like. steve
coil

http://cgi.ebay.com/ebaymotors/AMR-MONSTER-COIL-HONDA-TRX400-IGNITION-400-EX-TRX-400EX_W0QQcmdZViewItemQQhashZitem5885a03d72QQitemZ 380198993266QQptZMotorcyclesQ5fPartsQ5fAccessories

hotcam good deal too
http://cgi.ebay.com/ebaymotors/NEW-HOT-CAMS-STAGE-1-CAM-HOTCAM-TRX400EX-TRX-400EX_W0QQitemZ270456616135QQcmdZViewItemQQptZMoto rcycles_Parts_Accessories?hash=item3ef87874c7

[trx400ex07rider]

yeah cuz i was a lil confused because the directions for the jets said put the 170 dj in and that didn't seem right. oh i have a twin air filter, i just don't have it in my signature. what does the cam do though? and it goes on the axle right? how would the coil help with power? Lance

[honda400ex2003]

the hotcams control your valves to make them open further and longer to let it get more gases in and out. the coil makes your sparks better since it delivers more energy to the spark plug for every fire of the plug. this helps to create a better burn inside the cylinder. this would be a bolt on pretty much, you just have to take the stock one off with the spark plug wire, then put the amr coil on with the wire. the cam requires taking the head cover off, and replacing the cam. then adjusting the valves and such, after it is broke in you have to do the valves again to make sure they are in spec still. i would go with a 150 for now and see how the plug looks. you should keep the needle on the 3rd position, the pilot at a 38, and the f/a screw at 2 turns out and see how it runs. get it warmed up first. then change the plug. take it for a ride for about 15 minutes at different throttle positions. then take the plug out and see how it looks. if it is white then you need to go to up, black go down, brown you are good to go. steve

[trx400ex07rider]

thanks a bunch! all this help is really appreciated. oh i see how it all works. i'll probably get on those as soon as i earn some $. Another question i have is, while taking the carb out and rejetting, can i really hurt anything? ive been real cautious with this because it's a new bike and i don't wanna hurt it already and have to take it to the shop for atleast a weeks worth repair. Also, if a get a wider axle, i should get wider a-arms also? Lance

[honda400ex2003]

no prob on the help. unless you jet it too lean it will be ok. it is pretty hard to mess anything up when just doing jetting. just make sure you get it right before you go take it for an hour or two ride. this could cause it to over heat or burn a hole in the piston if it is too lean. with the wider axle, it is a nice combo to get arms and such too at the same time to really feel the most stability increase but alot of guys run with just a wider axle too until they get some money for shocks and arms. I run spacers when i am just trail riding every now and again if i know i will be riding stuff that requires more stability and never have problem. I will probably be getting a new axle and such this summer for mine but for the time being it is stock width. If you have the money i would suggest getting a wider axle first then arms and shocks later if need be. lol. steve

[trx400ex07rider]

sweet, cuz i was really worried about hurting something. oh i gotcha, ill get the axle then the arms when i get some $. Ive had problems with rolling it so far because of the stock width. when i take the gas tank off, what should i do to disconnect it from the switch to turn the fuel on off or reserve? i didn't wanna get gas everywhere in the garage so i didnt touch it Lance

[trx400ex07rider]

I also have a few more questions: with only the air lid off i should just bump the dj up 1 from the 142? and how do i remove the spark plug? i know where its at and all but idk how to remove it.

[honda400ex2003]

i would say that if you take the lid off i would start with a 150 and see how it is there. usually i would go up two jet sizes with the lid off but it is better to start a bit rich. just put the essential parts back on to test ride it before you finalize your jetting. you may end up at a 148 or 146 but i am not sure where you are at so at sea level you may want to go to a 150, at about 1500 ft you could try a 148 dj if you have one in the kit. also on the spark plug, you should have a tool in your kit that you can get it out with. you just have to stick it up in there and get it on the plug. get it from the left side of the machine so the exhaust is not in the way. take the bar that is in the kit also and use it in the 2 holes to turn the plug out. steve

[trx400ex07rider]

im above 5000 ft. ya so i dont kill the cylinder. i dont have the tool tho

[honda400ex2003]

i know there is a certain socket that you can use but i am not sure which size it is. if you search for spark plug tool or something in the 400 section you should find it. I know there was a question a few weeks ago on that subject. some of the sockets need to be ground down a bit on the sides to get it to fit in there. the tool is handy since it is made to go in the hole for it. lol steve

[trx400ex07rider]

i meant im at 1500 ft ha bad typo, i got everything out, now im confused on my jetting ha cuz i thought the jets i got in the fmf pack were main jets but the theres only these smaller jets that idk where they go cuz they deff. arnt fuel mixture screws so they have 2 be poilets. im just confused now lol

[honda400ex2003]

there will not be any f/a screws. there is no such thing. lol. if they are long and have holes in a shaft hanging out of them they are pilot jets. if not they are mains. there may be an adaptor in the kit that you ahve to use. otherwise if there is a number on them cross reference them with your direction sheet. they will tell you what they are. i doubt that there is any pilots in the kit so you will have a needle, adaptor that is threaded outside on one end, and threaded inside on the other. that should b inside there already, the round jets just screw into the adaptor.

http://www.dynojet.com/pdf/Q107.pdf

that is the dyno jet kit stuff incase you dont have your directions. This one shows all of the different parts that came in the kit. the pick should be the one that you have and where each of them are located. the fmf if i am not mistaken is a dj in different packaging so it should be the same stuff. the new kit has a f/a screw adjuster in it but the old ones dont. the new carbs on the 05+ carbs. the older ones are on the front of the carb on the bottom by the bowl in a cylinder. it is outside the carb. steve

[sc400ex_rider]

Originally posted by trx400ex07rider
thanks a ton! that answers my question perfectly, i'm gonna do it all tomorrow, im doing a stage 2 by taking the air lid off. what other mods would you suggest for more power? preferably on the cheap side

do the choke mod and adjust the slack out of the throttle cable to get full throttle.......

[trx400ex07rider]

oh then they are main jets, i got the adapter out but it doesnt screw into that so what if i take the next gold screw out from under the main jet thats in right now? the choke mod? u mean remove the choke? sweet ill try it

[honda400ex2003]

you can take out the choke flap and the bar for it inside. then you can bump up the pilot jet to a 42 and you would be able to get a bit better throttle response. do this after you get it running correctly with the lid off and such. you dont want to start doing all of the changes at once and getting it all messed up. the main jets just screw into the adaptor that is in there already. I cant find a picture right now but there should be a peice that stays in there, then the piece that the jet screws into. steve

[trx400ex07rider]

ya i'm taking a look inside. idt i have a 42 pilot jet for when i do that lol ya thats a good idea. i got confused because my main jet that i have in there is a different size and shape then the fmf main jets i have, its taller and much bigger so that's what confused me because i thought that was an entirely different jet all together lol i deff. have a lot to learn huh? i almost wish i could have some1 to talk 2 to walk me thru this. i really appreciate this help tho!!! i'll take a look for it. the only thing is, what if i need to ride in wet and muddy conditions with the lid off? wont it harm the engine? and could i get a k and n air lid cover in place of the lid? Lance

[honda400ex2003]

you will definitely have to be careful of water if you take your lid off. i have an ehs lid that is pretty good along with a k&n outerwears on my filter to help keep the water out. this combo seems to work pretty good since the water doesnt penetrate the outerwear material on either of them since the holes are small enough to offset the surface tension of the water and not let it go through. the k&n is also a good option to help filter and keep the water out. other than that you will have to read the directions on the kit and pop some stuff in there and try it out. the best way to learn is to do and redo when it gets messed up lol. good luck bro. if you get stuck take some pictures of where you are at then i can help you with it. take a pic of your jets, your carb with the bowl off and of the jets inside so i know what ones you are using compared to the one that was in there. Steve

[moddedblaster20]

geez ive been learnign quite a bit through reading these few pages myself haha. im in the diesel field so not familiar with this stuff much. i heard somebody on the last page say adjust the slack out of your throttle cable, how do i go about doign this? my thumb throttle can be pushed backwards some, i dont think this is normal haha. anything i can do to fix that? thanks, sorry for kind of goign off topci a little bit. quad is a 2002 400ex

[trx400ex07rider]

I was thinking about getting a k&n but from numerous people i have heard they let dirt particles in and it breaks the engine so i have always used a foam filter such as twin air, no toil or uni. what about the k&n powerlid? it seems like it would help atleast. is this the ehs u use?

http://www.ehsracing.com/products/400ex_airbox_EHS.htm

ya thats what im doin, until i screw up ha as soon as i find a camera where i can actually make out what it is ill get it on here asap. Lance

[honda400ex2003]

Originally posted by moddedblaster20
geez ive been learnign quite a bit through reading these few pages myself haha. im in the diesel field so not familiar with this stuff much. i heard somebody on the last page say adjust the slack out of your throttle cable, how do i go about doign this? my thumb throttle can be pushed backwards some, i dont think this is normal haha. anything i can do to fix that? thanks, sorry for kind of goign off topci a little bit. quad is a 2002 400ex

you can do this right on the throttle assembly on the bars. all you have to do is slide the boot back and then turn the knob out to get the slack out of it. you will be able to tell when it is just right since it will start to pull just as you hit the throttle.

trx, that is the lid that i use. both of them are pretty good though. I like my lid, but have never tried a k&n lid. sounds good on the pics. steve

[moddedblaster20]

thanks alot man! and i run a K&N filter with an outerwears cover and dont have any problems. a K&N is a great filter, just keep it clean and oiled

[honda400ex2003]

no prob bro, good to hear that i could help you out. steve

[moddedblaster20]

ill give it a shot tomorrow and let you know. i just want to fix the part where my throttle can come backwards lol

[trx400ex07rider]

ya thats deff. a good idea to fix your throttle lol i may take the slack out of mine. The only thing with that lid is its 80$ and i would have to cut the OEM lid, ud much prefer to have a whole different lid all together just in case i ever need to go back, any suggestions? and blaster, does the k&n filter itself give u any more power?

[honda400ex2003]

you can get one that is already together. that is how i got mine. the kit is one way to do too though. you could buy one online and cut it up if you wanted too to make your own. I really like my k&n too, you just have to make sure you keep it oiled and such to make sure nothing gets past it. i have had mine for years. I think i got it in 05. steve

[moddedblaster20]

my K&N seems to hold up fine and i even have an aluminum aftermarket airbox with no lid. i bought it that way, rode it for a day when it was muddy, after that went and got an outerwear cover for it. but i was bored one day and designed my own lid for it to put on when its wet out. cut a piece of plexiglass to match the airbox, drilled holes over top the battery, then velcro'd the plexiglass and airbox. seems to work, well at least keep most of the mud out. haha

[trx400ex07rider]

oh you can? from the ehs website? ohh i see, i may get 1 as soon as i get some $. thanks guys, ill deff. purchase 1 to test it out. are the aluminum airboxes any good? ive heard they give u extra power and i'm trying to squeeze all the power outa my 400 as possible

[moddedblaster20]

it seemed to help a little bit since its completely open, but liek i said i made a cover for when i ride in mud or water.

[trx400ex07rider]

quote:
you can do this right on the throttle assembly on the bars. all you have to do is slide the boot back and then turn the knob out to get the slack out of it. you will be able to tell when it is just right since it will start to pull just as you hit the throttle.


how do you adjust the slack on the throttle? idk what the boot is so help me out lol

[trx400ex07rider]

nevermind lol i got it, thats a real quick and easy way for a lil more power

[honda400ex2003]

good to hear lol. did you get your filter and such yet, and get it jetted right? steve

[trx400ex07rider]

i dont have any $ for the filter quite yet and im still a lil afraid ill screw something up, because i can do the main jet up to 150, no problem there but the needle, idk how to even get that out and i dont have any bigger pilot jets. plus i had the shop do my 1st rejett and im assuming they turned the fuel mixture screw 3 times so do i have to turn it again more?

[honda400ex2003]

the needle is under the top triangular cover on the carb. you have to loosen the two brass screws holding the arm on and slide the slide out of the housing. the needle sits under the arm and in the slide. you will be fine to jet the machine. it is not like you can really screw something up going with the recommendations. it should just about be perfect for you. you wont need to do anything with the pilot yet until you take off the choke or something either. all you have to do with the f/a screw is turn it in till it is lightly seated then you can turn it back out to where you want it. this is not a major part of anything on the machine, it just fine tunes the mixture so you get it running at its optimum performance. other than that you will be fine to try out taking the lid off. take it as a good experiment. lol. if you dont like it you can go back to what it was. along the way, write down what jet you took out, how many turns out the f/a was when you turned it in. do this by counting how many turns you turned it in to get it seated again. mark where your needle is and you should be ok. you may not even have to mess with your needle yet if you just take your lid off. go back and check out the jetting. i think it was about a 148 dj main, 3rd needle position(stock), 38 pilot (stock) and 3 turns out on the f/a. see how it runs, you can leave it apart and take it for a ride. then once you get it together a bit check the plug. depending on how it looks you can leave it or fix it. you can also experiment with the needle positions and such. move it up and down to see how it changes how it runs. you can then learn first hand how to feel when it is running best and when it is not.

"Don't be afraid to go out on a limb. That's where the fruit is."

steve

[trx400ex07rider]

ohh i get where the needle is

[honda400ex2003]

go tear into it now LOL. steve

[honda400ex2003]

steve

[trx400ex07rider]

ohh i get where the needle is, just gettin it out lol thanks man, all this is super appreciated. the pilot is god news. does the f/a screw "sit" into position or do you just have to tune it? thats deff. a good idea to write it all down. the only thing is i need to get the plug screw thing so i can remove the spark plug ha when i take the needle out tho, isnt there washers and such in there?

thanks a s***load man!!! Lance

[trx400ex07rider]

thanks for the pic also

[trx400ex07rider]

i would but here its 11 oclock lol got school in da morn but 2marro evening im redoing it all up, making it a monster lol

[honda400ex2003]

no prob bro you are welcome. that is why we are here. it is 11 here in Houghton too. lol. i cant even think about riding my machine till next weekend when i get to go home from school. so you are lucky to even get to see it sitting there. lol. good luck with it tomorrow. I should be on most of the evening so if you have any trouble let me know and take some pics so i can see what you are doing. lol. steve

[trx400ex07rider]

o so ur in college? ya its nice to just go out and day dream bout it lol thanks, i found a camera so yes! im gonna start now but i cant ride it due to 7 degree weather Lance

[honda400ex2003]

yeah i am in college full time. I go to michigan tech, it sucks seeing everyone with their snowmobiles around campus and such, knowing that mine is at home. lol. i wouldnt have time to ride it anyway so i guess it is a good place for it along with the 400 and f4. they stay at home for the weekends. it makes going home that much better.:D Good luck with the machine. all will go good for you. heck with the 7 degrees i would be riding anyway. lol. that is what gloves and full face helmets are for. lol steve

[trx400ex07rider]

sweet i cant wait 4 college. ya thats gotta suck. ya busy. live far from home? thanks man, i would but the snow is too deep. Lance

[honda400ex2003]

im always busy, lol. i am going for mechanical engineering and am a junior this year. lol. I guess i am not that far from home at 3 hours but it isnt like i can hop in the car and go home for the night and ride. this past fall i brought my 400 up for a few weeks which was fun though. how did it come out for you anyway? we have about 144" of snow for the year. it makes it hard to have the 400 at school when i snow blow every day lol. steve

[trx400ex07rider]

in college u gotta be lol ur else ur not gettin ur $'s worth. sweet, ya i getcha just a lil too far. sweet, havnt gotten to it cause of hw, projects, family over, sports practice etc. but im gonna put a 150 in it and also, i put the bare minimum on it and ride for 5 mins and its runnin fine but its making a faint weird sound, i think its cause of a cable i didnt put bak in the right place, its the long thin 1 attached to the very bottum of the carb, where u take the nut off to get to the main jet, where does it go? ya too much snow sucks im sick of winter. Lance

[honda400ex2003]

the one that comes out of the bottom that just dangles goes down between the swinger and the motor mount. if that is the one i am thinking of. lol. otherwise it is not a long one but there is a cable for the idle that mounts to the carb and around the bottom of the bowl. i think that may help you out sorry about taking so long. lol. steve

[honda400ex2003]

11 and 35 i think are the 2 am a talking about. the only other one that would be a cable is the throttle cable. it goes through the top and screws into it. this goes down through the black part and hooks to the arm. otherwise it goes on top of the shield and under the tank. steve

[trx400ex07rider]

I have it dangling between the swingarm and the motor mount as of now and i took picks b4 i took it apart and it looks like thats where it goes, just wanted to make sure because of that lil faint sound im hearing. np man i got time ha Lance

[Bwetzel55]

Not trying to steal the tread but since you were on the topic of jets what would be good to run with a fmf power core 4 full exhaust with a k&n air filter

[honda400ex2003]

about a 160 would be a good starting point i think. this along with the 38 pilot, 3.5 turns out on the f/a and needle on the 3rd clip position and then go from there. you may have to drop down to a 158 or so but it depends on where you are at. steve

[trx400ex07rider]

I just put the 150 main jet in my 400 and the idle speed is really fast, i can adjust that on the screw on the bottum of the carb but sticking out to the side right? and I wanna check the spark plug so i took the rubber piece off but when i tried to take the actual spark plug out it wouldnt twist out, ideas? Lance

[honda400ex2003]

you can turn the idle down with the big knob that has the black tube coming out of the back of it. there is actually a way to do it right though while tuning the f/a screw and the idle at the same time. if you do a search in high idle or fuel/air screw adjustment there should be some directions somewhere. or if you have a manual it is in there for sure. the plug can be a bit of a pain to get out, just make sure it is down on the plug all the way and start turning i guess, it should come out after a bit of turning. the threads arent that long. lol. the tool sort of clicks on it, you should feel when it grabs on the plug, you may have been hitting just above it on the head making it feel like you got it on but it wasnt. there is a nut on the top that almost feels like it is right. If you turn your gas off and stand it up on the grab bar you should be able to see in there and then get the tool in for sure. it is easier than trying to get your head in there to look for it. steve

[trx400ex07rider]

yeah thats the screw i meant to try and explain ha i'll take a look for those directions. yeah i got it on the plug but it's so tight that im pushing the socket as hard as I can, im not the strongest person but i was really pushing it and it wont come loose. i'll try again here, ill keep u updated. thanks. lance