400ex Not Fast Enough!!!

[HondaRacing23]

I have a decked out 400ex with a full fmf exhaust system. I have a k&n jet kit with a 142 main and stock pilot. my friend just got a brand new 04 completly stock 400ex and he can take me. should that even be possible or could there be something wrong with mine. i have been having problems getting. if i put what K&n says to put in it runs like crap but with the 142 it runs great but seems like its getting to muc fuel. i might try taking the air screw in a half a turn and see where that gets me. but as fo rhim taking me on a stock 400ex whats the deal? any ideas??? Thanks

[hondarider2006]

he's a better rider than you maybe?:blah:

[HondaRacing23]

hes never riding a bike in his life until now!!

[lilpoppy]

It has to be your jetting then.

[Sportrax10]

2004s have 38 mm carbs I beleive.

[Atreyu]

What's your tire and sprokect sizes?

[HondaRacing23]

i have itp holeshots xcr 20x11x9 rear sproket is 38 i think and front is 15 or 16 not possitively sure. what should i be running and opinions...

[offroadfury]

Could it be the fact that his is Brand New and yours is a 2000? Its probably about time you freshen up your top end, then the results may be different.

[HondaRacing23]

how do i "freshen" up my top end?

[offroadfury]

Take it to your local shop or do it yourself. Run a compression test on the cylinder. I'm not sure on the spec for a 400EX but it should be in the service manual. If it has alot of hours on it then with it being 4 years old your compression is likely to be on the low side. They would hone the cylinder or if there were any deep score marks they would have to do a rebore. Now if I were you i would raise the bar a little and just get a 440kit. That REALLY wakes the 400EX up. Then you wouldn't have to worry about him outrunning you anymore. Or, if your compression is fine and you don't want to do the Big Bore and if you don't weigh much(under 180lbs) i'd get a 16 tooth sprocket and not tell him about it:D That will increase your top speed quite a bit. I know a guy that put a Hotcam in his and it made a pretty good difference. There is a world of possibilities:blah:

[HondaRacing23]

isnt theres lots of things u need to change in a 440 though. doesnt it pretty much act like a banshee high maintance. i dont race very much and want to do some hair scrables in the spring. i have heard a lot of bad things about 440's are they really or is it just as much maintance as a 400 thanks

[Paul400ex2002]

440 kits aren't all they're cracked up to be. You have to get a lot more stuff to make it run efficently. Upgrade the oil system, all that crap. A well built 416 is a really good option because you save another bore in case you have a problem, and you can still make a lot of power. My 416 with the stage 2 hotcam is a major increase over stock, especially on top end. Once I get the FCR39 and Sparks X6 it will really wake up. BTW I'm running a 12.5:1 JE 416 piston with the stage 2 hotcam and a white brothers e-series muffler.

[HondaRacing23]

what about the 426 kit is that a good change. i just want to be able to beat all my friends that think they are the best when they really arent sh&% ya know how that goes.... i dont want to spend more than like $400

[cals400ex]

1st: your tires are heavier than his. this will make you loose acceleration. it will probally be noticable too.
2nd: i don't use dynojets so i can't tell you what jet to use. the mainjet is what controls the fuel at 3/4 to full throttle. so, the fuel skrew won't do anything for full throttle. this is what you can do though: take your bike out and get it up to full temp. find a long straight away or road or anything. floor it through all of the gears until you have dead top end. quickly pull in the clutch and shut the bike off. leave the clutch pulled in as you roll to a stop. take the plug out and see what it looks like. i like it when my plug changes from a gray to a tanish color right on the bend of the plug. you kind of have to look, but it is noticable. if the tanish color is closest to the tip of the plug, your a little richer than i like to be. if the tanish color is closer to the bottom of the plug, your a little leaner on the mainjet than i prefer.
3rd: make sure your throttle cable is adjusted properly or make sure there isn't a ton of slack in it. this makes a big difference.

[hondarider2006]

my neighbor has a '99 400 with a white brothers slip-on, k&n filter, jetted, and no air box lid, "22 razr rears....my old 2000 400(the one that got stole...:mad: ) was completely stock, except renthal bars, and it beat my neighbors 400. I know for a fact it wasn't cause he lacked riding skills, cause he would kill me on the track, trail, pretty much anything that wasn't a straight paved road.....So my guess is that a new top end would do you a lot of good, or a 416 kit with a stage 2 hit cam. I am thinking about going with the 416, but I want better suspension first:devil:

[HondaRacing23]

So how much am I talking price wise for a 416 kit. i plan on taking everything apart myself and just having it bored by someone else. I want to leave the air box lid on because i do a lot of muddy riding will it still run good with it on with the 416 kit? I know the jetting is probably going to be different and ideas what they should be with the k&n jet kit? thanks guys....

[dirtmomma]

Originally posted by offroadfury
Could it be the fact that his is Brand New and yours is a 2000? Its probably about time you freshen up your top end, then the results may be different.
My thougths exactly!! My 300 was runing like crap cuz it was WAY low on compression maybe you should check your copression I bet it's low, O I just seen someone else said this too sorry for the double post:rolleyes: Don't knwo about you but I don't have all kinds of $$$ to be putting kits in so we just had it bored,new piston,rings, & now she's running like a champ!!!! & that was about $150 for parts MAYBE!!;) Just trying to help ya save some $$ sincce you don't race it big time.

[HondaRacing23]

i think im just going to call my local shop and see what it will cost for a 416 kit...

[dirtmomma]

Originally posted by HondaRacing23
i think im just going to call my local shop and see what it will cost for a 416 kit...

:eek2: :eek2: Oh man you must have some $$ cuz they charge a FORTUNE!!!! Are you goin to have them do it???? If not I would order your parts online or from a catalog it'll save you lots of $$$ just a suggestion!!:D

[Crawl69]

Why don't you just give Colby a call, he has a fair price.

[HondaRacing23]

who the hell is colby

[sweet300ex]

A co owner of C&D Racing, the site sponsers

[HondaRacing23]

as if i can get him to do something for me for a pretty good penney.... ill do it myself i know pretty much what im doing..

[mikeboone]

Originally posted by HondaRacing23
as if i can get him to do something for me for a pretty good penney.... ill do it myself i know pretty much what im doing..

They are talking about buying the parts From Colby (C&D Racing) not you sending the motor to him. He has great prices and much better service than you will find at your local dealer.

[HondaRacing23]

what is c&d racings web site?

[trailburner]

It's on top of the page.....................just click....;)

[hotrodhonda400]

Originally posted by Sportrax10
2004s have 38 mm carbs I beleive. he's right ours have 35mm carb i beleive

[Paul400ex2002]

I spent a little over 600 bucks on my 416. That was with the cam and having the head rebuilt. I also had someone else build my motor, and that was about 200 bucks.

[cals400ex]

stock are 35.5mm carbs. i don't know, like many others, with the 04's.