2004 38 carb question??? COMPARISON

[tahoe97]

I was wondering how much better the new 400ex will perform with the bigger carb.. will people with the older carb that is jeted be able to keep up with it or is it just going to be alot faster??


i guess what i mean is how does it compare to a jeted older model 35 carb??

Thanks guys

[skemp]

I just noticed today that the '04's had 38's. I must have overlooked it. That should boost power a bit. It should definitely respond to mods better anyway.

[toby400ex]

I would think it would just boost it a lil on top end:ermm:

[tryken]

Anyone know or have an estimate on what the 38mm carb from a Honda dealer would cost? I am thinking about upgrading if it is not too expensive.

I am glad to see that Honda put the 38mm carb on the new 04EX. Does anyone know what machine they got it from, maybe the new one they are working on has a 38mm.

[kargaaro]

Carbs are usually expensive. If you're gonna drop money on a new carb, go with the FCR 39 - Sparks Racing $450 all set up.

Originally posted by kargaaro
Carbs are usually expensive. If you're gonna drop money on a new carb, go with the FCR 39 - Sparks Racing $450 all set up.

Good point (its less $$ at C&D but) but I am wondering what the difference is between the two carbs in design, performance and price.

Does anyone know?

[Chanman420q]

how much is a stock carb now?? it cant be much more

[tryken]

Yeah but, the 38mm on the 04 would be a stock Honda part, that is why I am considering getting one. But if it is too expensive I wont worry about it and just stick with the one that came on my 01.

[YZROOSTINYA]

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Item Number Description Qty-Pack List Price Each Discontinued Our Price Each
16100-HN1-003 CARBURETOR (QB10A A) 1 $300.15 $198.13



200 from service honda

so prob 300 for the new carb since it is a newer model and the price will be more

I would rather have a stock 38mm honda for 300 then a 39 fcr for 400

[tryken]

I would rather have a stock 38mm honda for 300 then a 39 fcr for 400

Me too.

[shaneb]

then whey not use the STOCK fcr 40 off the cfr450 ????

Do not waist your money on the 38, it is still a cv carb.

you can get a pre jetted fcr from sparks etc .....

[YZROOSTINYA]

because the fcr 40 is for thr 450 and it mounts differantly and its for a twist throttle

plus the 450 carb is $354.16 from service honda so add 15 for shipping. its 500 at the dealer

the 38 should be less.

you dont need all that carb. the 450 puts out 50 hp, my quad doesnt, prob around 35

[H_W]

I don't understand why you would rather spend 300 for a stock carb instead of 400 for an fcr 39. The fcr is a much better carb. I put the fcr on my quad and I can tell you that it made a huge difference in overall power.

[tryken]

Because it is a Honda part. I had no inclination to get a new carb until I found out about the 04 having the 38. I can upgrade my bike using a factory Honda part. I hope that makes sense, at least it does to me.

[H_W]

I understand what you mean are talking about now. I was just thinking from a performance standpoint, if the stock one costs 300 and the fcr costs 400 the hundred bucks difference is well worth the gain in performance over the stock carb. It is not necessarily the size of the carb that makes all the difference, it is the design. The fcr is a designed to flow better that the stock carb on a 400ex. The fcr is the same design of carb that is on the crf450 dirt bike.

[shaneb]

tryken I think you are aver estimating the value of a "factory" part.

As well you are underestimating the power diff when you move away from a CV card.

Get the fcr 39 you will be happy !!!

Shane

[cals400ex]

is there anywhere we can read about the new 04 carb to see if there is any power difference? also, is the fcr the best carb you can buy for the 400ex? i know edelbrock and a few others make carbs but i don't know what will give the most power.

[Chanman420q]

ITS NOT THE SIZE OF IT, ITS THE WAY YOU USE IT!!

[excess]

Personally I don't think the price of the carb is gonna change, This is not a performance part it would be considered a replacement part which is why it won't have the high price, honda shouldn't charge you more bcause it is a 38mm. I think it would stay at $198.

[UglyMotha™]

Originally posted by Chanman420q
ITS NOT THE SIZE OF IT, ITS THE WAY YOU USE IT!!



dear god i think your in the wrong thread :huh


i think there's a little fellars club a couple sites over :eek:

[EX 80]

Wow that will be the day that i'd ever replace a perfectly good working stock carb for another one. Wu hooo and extra 3mm. If you going to spend money for another carb looking for a gain get an FCR. :rolleyes:

[BigThumper33]

Why would you buy an OVER priced FCR39mm when you can buy a FCR40mm from servicehonda for cheaper?

Mounts different? I don't know about that. I have a friend who has a FCR40 mounted on his Z400 and it is working great. I'd go with a FCR40 if I were upgrading.

[avc8130]

yeah, but this new carb does have an accelerator pump. this means it might be something decent. prolly not as nice as an fcr, but definately nice for a stocker
ac

[remlapr]

If the new carb does have an accelerator pump and sells for around $200 - they will probably sell as many carbs as '04 400EX's.

[YZROOSTINYA]

ex 80

actually it is 2.5mm and yes it does make a diff.

why do you think that people go the fcr 39, its only 3.5 mm but it makes a diff.

Can you use the thumb throttle with the fcr40 that comes on the 450f bike?

what are the gains compared to a fcr 39

also 200 bucks is not bad compared to 450 for a fcr.

i am not looking for a carb but if the 38 was not that pricey and it had decent gains i would pick one up

[avc8130]

yeah, you can use a thumb throttle with the 40mm. gtthunder.com sells a cable for it. you have to call them its not on their site though.
ac

[tryken]

I am in the same boat as yzroostinya, I am not necessarily looking for a new carb but if the new stocker is reasonably priced and is worth it I may get one. If I was just looking for a new carb period I would probably take your advice and get the FCR 39 or 40. Thanks for the helpl.

I emailed Service Honda to see how much the new carb will cost. I will let you all know when I find out and see what you all think.

Originally posted by tryken

I emailed Service Honda to see how much the new carb will cost. I will let you all know when I find out and see what you all think.

I called service honda yesterday and he stated they have no price list what-so-ever for 2004 TRX400ex quads...he named a few other model bikes but no quads. I think when the quads hit the dealer floors thats when service honda will be able to purchase the 04 parts...at least that's what i got from the guy on the other end of the horn....:)

And for $200 I'd pick one up before payin $450 for the FCR which still requires the purchase of a $30 fuel screw to be dialed in properly.. heck you could even send the new 38 off to some place like Rocky Ridge have it honed out even more for $100+ bucks so your $325 in cost and have a nice carb built for your motor.... can I get a hell yeah....:D

I"m not sayin the FCR is not the way to go or worth the money but for us budget shoppers the new 38 carb is the ticket and honda's gonna have one hell of a time keepin them in stock i think if the price is right at $200..

[UglyMotha™]

yup i got a 38mm carb on my bike and it's a very noticable difference and if i came along the path again i would still go with the stocker for 200 bucks or even rocky ridge will do the 35.5 for 125 and i don't see the fcr making that big of a difference that would be worth the extra 300 buck, thats my opinion though

[Pappy]

ill try that sucka out:macho for $200 or close to that it should make a noticable improvemnet over the old carb....and if they redesigned the accelerator pump and who knows what else it could be the hot ticket:D


as far as those complaining about it being a stock part......i reckon you arent true gear heads because chevy, ford and mopar had stock parts that would make a huge differnce over other stock parts in performance:o

[Burden7]

I have a 38mm Keihin bored out to a 39.5mm and I just replaced it with an FCR41 that isn't dialed in very well and the FCR performed way better than the other carb. The stocker carb is still a round slide carb and it will not perform as well as a 1-2mm smaller flat slide carb. I find it kinda funny that people won't pay a couple hundered bucks more for a better performing carb, but go out and spend about $300-$400 more for Elka shocks over Works shocks?? :confused:

[Pappy]

ive seen every carb imaginable used and to be honest the gains from one to another didnt validate the cost. if most people would take the time to properly set up a stock carb maybe it wouldnt seem as such a big gain. there are draw backs to using the larger fcr and other type carbs...especially on a stock engine.


as far as spending money:confused: there are certain places money is better spent....ill pour money into suspension before engine any day of the week;)

[Burden7]

I would say that if you have any internal engine mods done, then the next step would be an FCR carb. I didn't think a carb made that much of a difference. I kept buying different sizes of round slide carbs and even a smaller Mikuni flat slide carb. And none of them out performed my FCR that isn't dialed in. I could have bought 2 FCR41's for the money that I thought I was saving by buying the cheaper, less performing carbs.

I think it is along the same lines as buying shocks. If you buy the cheaper/less performance shocks, you are cheating yourself and your quad out of maximum performance. It is the same as buying the cheaper/less performance carb, your are cheating your engine out of its maximum performance. But for the everyday trail rider (which is the majority of this board) the new stock 400ex carb will be a nice upgrade.

[YZROOSTINYA]

first off there is a HUGE diff between works and elkas

when your referring to price diff

the low ball works are smaller shafts and the elkas are 5/8"

if you go for the better works they are almsot the same price and then your prob just paying for a pretier shock


second if I can get 4 hourse out of a 200 dollar carb and 5 horse out of a 450 dollar carb i will spend the 200.

3 there prob gonna be about 275 bucks which will put it inbetween the stock 35.5 at 200 and the 40 fcr for the 450 f at 358

JMO as usual

[ROGERS]

The stock carb is a CV?:huh Don't CV carbs operate the slide by vacuum of the engine? I could have sworn that when I move my thumb throttle that my slide goes up, even with the engine off.... And when I was fiddling with the needle setting, I didn't see any rubber boot under the lid.....

CV=Constant Velocity, in case anyone was wondering. If the engine is rotating slowly, the slide (which is operated by the vacuum of the engine) will be closed more, no matter if you yank the throttle open. Then if the engine is spinning higher, the slide will open farther ("further" maybe the right word). Your hand operates the butterfly, the RPM operates the slide.

If I am wrong set me straight, b/c I may think I'm smarter than I am.;)

[UglyMotha™]

if your talking about the stock ex carb no it's not vacum operated if your talking about some other carb i have no clue



matter of fact i heard some people over in the non-honda forum talking about putting the 400ex's carb on there z 400 because there not vacum operated where as the z's is

[avc8130]

putting the stock ex carb on a z400 is a possiblity. it does not really improve performance too much, but throttle response is much better. the CV carb really kills the z400 motor down. the stock ex carb is more of what should be there from the factory, still leaving an upgrade to an fcr at a later date.
ac

[remlapr]

Does the stock carb have an accelerator pump? I didn't think it did - but I could easily be wrong. I though the accelerator pump was part of the reason for upgrading to the fcr? I though that was what increased throttle response and got the rpm's building quicker??

[UglyMotha™]

yup the stocker has an accelerator pump that is why your are able to start it with out the choke if you up the pilot size you just pump the throttle a couple times and she fires right up

[remlapr]

Well in that case - I wonder how much the $125 bore job to the stocker would help with only a slip-on and filter?

[Burden7]

I though that was what increased throttle response and got the rpm's building quicker??

The reason for the increased throttle response is because the FCR is a flat slide carb and the stocker is a round slide.

[UglyMotha™]

Originally posted by remlapr
Well in that case - I wonder how much the $125 bore job to the stocker would help with only a slip-on and filter?


on my motor it made a big differance

as far as the stock motor there must be a increase or else honda wouldn't have done it

[remlapr]

Originally posted by UglyMotha™
on my motor it made a big differance

as far as the stock motor there must be a increase or else honda wouldn't have done it


Yeah that is what I'm thinkin, I had always thought you didn't really need more carb until you had motor work done, but if Honda is increasing the carb size then there must be something to it. I wonder if they are increasing the compression???

[JD400exrider]

I did talk to one of the service guys at service honda and got basicly the same answer as Rico. No part numbers or micro fishies yet on the 04 quad.
His feeling was that for honda to put a bigger carb in they may have done some porting on the head or even a better free flowing exhaust than the old ones.

He told me something that i have not heard of and that is the XR 400 motorcycle head is a little different than the trx head. They bolt up and fit the same but the xr head is opened a little more Ported. Does this sound right :confused:

He also said that ordering that new carb directly from Kein would lickely be cheeper than ordering it from honda corp.

This new bigger 04 carb has me holding off sending the stocker to sparks for the mod or buying a FCR. We should know something in the next month or so on the new 04.

[JD400exrider]

CARB SHOOTOUT in ATV Action Magazine
January 2002 Issue

Stock Carb
Edelbrock Quick Silver
Edelbrock Quick Silver 440 prototype
Keihn FCR 39
Keihn FCR 41
Lectron 38MM

Not going to get into all the specifics.
Test was performed on a 400 ex with a CT racing 440 national Kit

The stock Carb ties the power output with most of the carbs until around 5000 rpm. Around the 6000 rpm the stock carb signs off while the other carbs keep producing power.

Dyno Peak HP
Stock Carb 40.8 hp @ 7600 rpm
Edelbrock Quick Silver 42.8 hp @ 7700 rpm
Edelbrock Quick Silver 440 43.4 hp @ 7700 rpm
Keihn FCR 39 43.2 hp @ 7800 rpm
Keihn FCR 41 43.5 hp @ 7800 rpm
Lectron 38MM 43.6 hp @ 7800 rpm

Now is 2-3 hp worth $ 450.00 with these numbers. I am sure the 04 38 mm carb should give a 1-2 hp gain or a stock carb mod 1-2 hp gain I have been told that the stock carb mod has better throttle responce over the fcr 39 but the fcr will give better power on the top.

Just my .02

If you have the issue it is worth a look.

[Chanman420q]

Just a side question.... Would there be any diffrance just buying a FCR40 over a FCR39... other than the 1mm. Basicly what im getting at is, will this 1mm be to much for like a 416 or 426. Because if ur gunna get more out of the 40mm, then the 39 and the 40 is cheaper... i dont see why anyone gets a 39.

do the FCR40 from serivce honda come with that air Screw?

and

How much are those thumb throttle cables for the FCR40

[RIDER11X]

Does the new 40 still have the accelerator pump on it?

[Matt Fisher]

If the 400EX is getting a new carb, then it's very likely the motor will have additional upgrades. It would be quite un-Honda like to change a carb for no apparent reason. After all, it's worked just fine since 99.

The only other reason I can see is for emissions. If the new carb were a enviro-nazi friendly CV unit, then I predict that the old carbs will be a natural drop-in for the 04' bikes.

[Racer over 40]

I hate to bust everybody's bubble but I got to look over a 2004 Honda 400EX microfiche today at my local Honda dealer. They did not show any different part #'s for a possible 38 mm carb. The microfiche shows the same carburetor for the '04 as has been on previous models. The head, cam. piston are the same also. It looks like the 38mm carburetor was a misprint in the dealer propoganda. Unless, they screwed up on the parts microfiche which is highly unlikely. I just want to keep the 400EX brethren in the know!!!!

[UglyMotha™]

Originally posted by Racer over 40
I hate to bust everybody's bubble but I got to look over a 2004 Honda 400EX microfiche today at my local Honda dealer. They did not show any different part #'s for a possible 38 mm carb. The microfiche shows the same carburetor for the '04 as has been on previous models. The head, cam. piston are the same also. It looks like the 38mm carburetor was a misprint in the dealer propoganda. Unless, they screwed up on the parts microfiche which is highly unlikely. I just want to keep the 400EX brethren in the know!!!!



so are you saying honda ****ed up there own website also :confused:

just wonderin cause right on there very own website it has a 38 listed

[Racer over 40]

Ugly Motha, I understand what you are saying!! I was at our local Honda shop and asked my parts person if they had the new '04 400EX microfiche and he opened a envelope received Friday from Honda. I looked that microfiche over very closely and seen no mention or indication of different carburetor(38mm) or part #. It showed the same carburetor used on previous 400EX models for the '04 model. I hope you are right and Honda did do some badly needed performance updates but I am telling you what I seen..

[Racer over 40]

I would also like to add that I am currently looking at the Honda Redbook. This is the book the dealers get to preview the new models. Under '04 Honda 400EX it states " New features for 2004" Team Honda inspired graphics..... And that is it. But the model specifications show a 38mm carburetor as being on the '04 just like on Honda's website. But the '04 microfiche does no correspond with that information.. As stated before, I hope Honda has done some performance updates.

[JD400exrider]

Thanks for the update racer over40.
When does the dealer you work at expect these new quads to be trucked in? Maybe look and see what's on them. Let us know if you hear anything different.

[Sick0]

The fcr 40mm carb doesn't really fit well. I had a lot of trouble making it fit. I had to modify the intake, there was adpter made to fit the air box work withcarb. the carb doesn't between the gas tank and the starter on the motor. you have to tip the carb to the side which effects the porformance.

When I git on and woking, there was a noticable stumbly in the low end. but theres was a lot of top end gain

[y2k400ex]

On hondas site
Carburetion 38mm piston-valve with accelerator pump 2004
vs
Carburetion 35.5mm piston-valve with accelerator pump 2003

The most simple thing for honda to do would just to take the 35.5mm carb and open it up to 38mm. I dont see honda making a totaly new carb for the 400ex.:ermm:

[Sick0]

It would still have a diffrent part number.

[cinigen9]

do you have a pic of your fcr40 installed?

thanks

[2001 trx400ex]

how do you no that the 04 400ex is goina have a 38mm carb and all this other stuff.

[tryken]

Go to Honda's website and read the specs on the 04 model.

www.hondamotorcycles.com

[dad400ex]

Honda already made one change to the the 35.5 carb. in the 2002 - 2003 models. Vent Hose mod. of which they had to change the casting for the boss,to add the hose and Y...Check it out !!!!
If Honda did that mod. I'm sure they could change it to 38mm....
On the michofiche,its listed as a option,because of the year changes,you would have to ask for the 2002 carb option to get the change,as you probably will have to to get the 04 change.And all would probably have the same part #

[RIDER11X]

I really think this whole carb issue is a typo. Honda doesn't usually make changes to it's models from year to year, with the exception of their CR line up which must change every year to remain competitive. The microfische info posted earlier is the proof for me.
However, mabey Honda is looking at the 400 class sport quads like the CR line up and they want to remain competitive in shootouts with Z400's and their clones. Who knows? We need some Honda engineers as members to give us the scoop!:D

Originally posted by RIDER11X
I really think this whole carb issue is a typo. Honda doesn't usually make changes to it's models from year to year, with the exception of their CR line up which must change every year to remain competitive. The microfische info posted earlier is the proof for me.
However, mabey Honda is looking at the 400 class sport quads like the CR line up and they want to remain competitive in shootouts with Z400's and their clones. Who knows? We need some Honda engineers as members to give us the scoop!:D

they redesigned there front hubs after 2001 and didn't tell anybody....:eek: I got a 2002 hub at home and it will not work on my 2001 model....:ermm:

I hope it is true and the price is low..cuz i'll be buyin one i think...:devil:

[Taco]

If this carb isnt a myth and improves power for around 200-300 I will be on it like stink on poop:D

[RIDER11X]

Originally posted by Rico
they redesigned there front hubs after 2001 and didn't tell anybody....:eek: I got a 2002 hub at home and it will not work on my 2001 model....:ermm:

I hope it is true and the price is low..cuz i'll be buyin one i think...:devil:

Really? Did the bearings change too? Does it require a 2002 spindle to fit? I never knew that. Thanks for the info Rico, I'm always leaning something on here.:)

Originally posted by RIDER11X
Really? Did the bearings change too? Does it require a 2002 spindle to fit? I never knew that. Thanks for the info Rico, I'm always leaning something on here.:)

I think they actualy changed the spindle design and had to change the bearings in the hubs to match....:ermm: A year or so ago there was a thread of all the things that have been added or chanced to the 400ex since it's birth in 99 and most people think stickers change and that's all but there's actually been alot of things changed...mainly small stuff but this carb thingy has got my panties in a bind wondering if it's true or not. Anybody got Mr. Honda's home phone number???:confused:

[YZROOSTINYA]

the carb boot changed also. My 2002 is a solid rubber boot over metal. the 99' just had the back half rubber and they were crackin.

the side plastic changed to allen screws instead of phillips.


there are some other changes also as rico mentioned.

I would not doubt if there is a newer carb set up.

It needs it

[RIDER11X]

Originally posted by Rico
I think they actualy changed the spindle design and had to change the bearings in the hubs to match....:ermm: A year or so ago there was a thread of all the things that have been added or chanced to the 400ex since it's birth in 99 and most people think stickers change and that's all but there's actually been alot of things changed...mainly small stuff but this carb thingy has got my panties in a bind wondering if it's true or not. Anybody got Mr. Honda's home phone number???:confused:
Do you by chance remember what that thread was called? Thanks.:)

[Sick0]

They change the steering stem too.

[excess]

Would there be any significant difference if this carb actually existed if I just bored my factory one now to 38mm?

[RIDER11X]

Originally posted by Sick0
They change the steering stem too.

They did? In what way? Reason being is I bought 2 spare OEM stems. (Don't laugh at me.......I roll over alot!:D )

[Sick0]

I'm not sure how they change them. I knolw they made them stronger. but dobn't worry there still not that strong.