carbs?

[Miami_Vice454]

what is the ifference bewteen all these different carbs. what is the stock 400 carb design? and what is a FCR, a flat-slide?

[4reeds]

I used a fcr flat slid carb 39mm on my 416 and loved it.well worth the money.I think the carb was from a yamaha dirtbike

[honda400ex2003]

as ish stated previously:

The 04-05 450R's do not run an FCR carb. They run a 42mm butterfly type carb. The 06-current 450R's run a 40mm FCR.

If the 04-05 were an FCR then why is it such a popular mod for the owners of the 04-05's to replace their carbs with an FCR?

Here are two exerpts from Honda's features and benefits of the 450R.

The 04-05 model.

42mm Keihin butterfly-type carburetor features light throttle effort, smooth operation and excellent rideability.

The 06-current.

40mm Keihin FCR-type carburetor features four rollers on the flat slide, resulting in very light throttle effort, smooth operation, crisp throttle response and excellent rideability.

there should be links in it. steve

[honda400ex2003]

didnt work

http://www.exriders.com/vbb/showthread.php?s=&threadid=448710&highlight=450r+carb

theres the link that i found from not long ago. it is not all of the carbs but will give you a general idea of what the fcr is and such. steve

[Miami_Vice454]

thanks man, but why do people use the 04-05 butterfly design, isnt the fcr a better design? and i would think 42mm would be overkill for a 416, but a 40mm would be perfect?

[honda400ex2003]

im sure someone will disagree but it is imo easier to mess with and mounts up easier when running an airbox. the fcr is taller so it hits the tank when connected to the intake tube and ran to the box. it then requires a bit more modding to get it to fit. Although, i have never used an FCR style and had to tune it so i cant really go off of the basis of the butterfly being easier to tune. I knew more about the butterfly ones since i messed with the 400 carb alot before switching. a spacer can be made for the butterfly and it will basically bolt right up instead of trimming and modding. if you dont plan to run an airbox the fcr is a great carb to run. the butterfly is also a bit bigger so that helps for top end increases but you do sacrifice a bit of low end for it.

lets hear the opposite sides from some of the guys that run the FCR setup. steve

[Miami_Vice454]

ok, and what about the YFZ 450 carb? its a FCR. is it easier to install?

[honda400ex2003]

not sure, there are a couple of guys that have done it though. Ill see what i can find. steve

[honda400ex2003]

from what others are saying about the yfz carb:

The yfz FCR is close in size to the 05 450r carb but smaller (shorter) than the 06 450r carb. The yfz carb is much better than the 05 450r carb but does require a little more patience tuning it.

there is also the z400 carb that is supposed to work. any info on that? steve

[CarGuy7a]

You can also make a stock carb a screamer if you know what you are doing. I bought a cheap stock carb for like $30 off ebay and did a few little things to it and couldn't believe the difference it made.

The stock carb's bore if you look at it has an oval shape with a W type shape on the sides. I took the W shape out of the carb to where it was a true oval. You do not want to take any material out around where the butterfly sits or the carb is junk. Doing that along with doing some slight radius work on the sharp edges and polishing the inside, makes quite a difference.

[honda400ex2003]

nice! any pics of the improved vs the regular by chance? IMO you should look at your riding style before buying a carb, each one goes with a ridin style and setup better than another. steve

[CarGuy7a]

I don't have any pics. I didn't take any when I did it. I did that carb a few years back and I'm still running it.

It started as an experimental type thing so that if I screwed it up I was only out $30 and I would just keep what parts were salvageable. But it ran so good I just left it on the quad.:D

I did have to richen up the jetting quite a bit. I started it up and the idle rpms were screaming with the idle screw backed all the way out. I had to richen up the a/f screw enough to where I could open the idle screw up some. Then I moved to getting the needle adjusted and that thing ran like a raped ape after that.

I took a short ride after it warmed up and the grass was slightly wet and I came up over the hill at my place in 3rd on a wheelie while in a power slide, un-intentionally. It definitely made me pinch the seat a little harder.

[honda400ex2003]

i agree with that, i liked my 400 carb alot. it wasnt real great for top end but it sure delivered the low and mid much better than the 450 ones imo. having it a bit smaller helps get it going faster but it falls flatter on top unlike the bigger bore carbs do. maybe if it is reworked a bit like you did it would be a bit more of an all around type of carb. give and take i suppose for now. lol one day i may get bored enough to try out the 400 carb again with my stage 2 and 10:1 setup and see how it is. I ran the 450 carb with both the stage 1 and 2 so i noticed the difference in that setup but i never got to run the 400 one like that. oh the experiments to try out lol. it never ends does it... steve

[CarGuy7a]

Oh yeah the possibilities are endless. I have heard on the other hand of some guys taking a stock carb and boring it to a bigger diameter, but then you get into changing a whole bunch of stuff inside such as butterflies and what not.

[honda400ex2003]

imo the 450 carb is also alot more finicky than the 400 carb is. i can always tell if the temp is a bit different or the pressures are different outside when i start my machine up with the 450 carb. it never really mattered all that much with the 400 carb it seemed to stay tuned alot better than the 450 carb does. just a bit of observation from my experiences with it. steve

[Miami_Vice454]

my kind of riding i think i would benefit from a little bigger carb. i think imma try the yfz carb. it seems like a good deal. and my neighbor knows how to tune those cause hes tuned his like 8 times. (all with different setups)

[honda400ex2003]

nice, anyone else have any input on the edelbrocks and such? steve

[rinconrider]

i have been hanging low the past couple of weeks just learning what i can about the 400. this thread has lots of great info in it! Keep up with the discussion, i am subscribed now. :chinese:

[CarGuy7a]

Originally posted by honda400ex2003
nice, anyone else have any input on the edelbrocks and such? steve

I've read some mixed reviews on the edelbrock carbs a long while back. Some liked them some said they ran like total garbage.

A guy at work has the Edelbrock carb and intake kit on his Raptor 660 and said it runs great. But then again that's on a Rapturd.

[Miami_Vice454]

ive also heard mixed reviews about the edelbrock carb. my view on that is if your are going to spend 400 bucks on a carb, you might as well buy the sparks carb which ive heard is the best but im only looking to spend ~150.

[yellow416ex]

From what I've read so far on the Edelbrock, people either love 'em or hate 'em. I found one for sale locally for fairly cheap so I picked it up, but I haven't been able to get it to run right at all. It didn't come with any different needles and I have no idea what elevation it was set up for. They're pretty simple to adjust, its just finding the right needle for it I guess.

I've had the best luck with the '04-'05 450R butterfly carb, although it a bit finicky like Steve said.

I don't mean to hijack the thread here but if anybody wants an Edelbrock Doug Eichner signature series- its for sale