39mm FCR Questions

[Quadzilla]

Hey guys,

I'm new here but not new to ATV's (since the 80's) or Honda ATV's (got the first 99 400EX in stock on Balt when it came out). Anyway, I'm getting ready to rebuild it at the end of this month. I am either going with a 416 or 440 kit (suggestions?). Now to the real question. I plan on also buying a 39mm FCR. I know that a lot of guys are buying them for fairly cheap at Service Honda (C+D carry them also?). My questions are:

1. What is a good place to start with on jetting? By default I would imagine that these are jetted for a stock CRF450? I ride in Southern PA which may be a couple of thousand feet above sea level tops. I currently have a Sparks Racing Full Exhaust and a Uni Filter in the air box.

2. I use a twist throttle now on my stock (but jetted) carb. It's a motion Pro unit. Can I keep this for use with the FCR? This is a single cable unit, not sure if the FCR has one or two cables (push pull). If I do have to get a new throttle and cables, what should I get (stock CRF throttle possibly, but what cables??)?

3. Is there any special installation tips (cutting of intake boots, tank clearance, etc)?

4 . Do most run this setup with or without the airbox lid?

5. Is it easier/better just to go with the Edelbrock carb kit. They give you everything you need and are close on the jetting right out of the box (or they say that anyway). My fear is that they are not as good as the FCR and they are more prone to issues. I see "rebuilt" edelbrocks being sold on Ebay. Wonder why they need to be rebuilt after only a year or so of use????

Wonderful to be here, it seems liek a great group!

Thanks for answering all of my questions!
Quadzilla (<--have had two of these in the past before my 2 400EX's)

[bradley300]

well, dont know the answer to most of your questions, but i have heard lots of people praise the doug Eichner (sp) series edlebrock

[416exmx]

i'll give it a try

1) ??
2) they are designed to use a push/pull or just a pull...you can use your twist throttle
3) may have to cut the snorkle tube a bit up by the carb. put a small piece of rubber between the tank/carb
4) i ran with lid vented with 6 - 1" circular holes with foam filter deals.
5) do not go with the edelbrock...i repeat do not...i had one and hated it...it was VERY hard on the ol' thumb. the spring on the accelerator pump is very stiff and they are hard to push. i even tried it with a twist throttle and it was still tough.. i also do not like the deal of them being externally adjustable...felt like i could never get it tuned in just the way it should be.

after this carb i went to a FCR on a 416 and loved it... i think they are the best carb out there. lots of people like the lectron 38mm i think...they are a cheap carb for the gains you recieve.

[muff]

first off you can probably get a jetting kit along with it, the 40mm fcr carb is from the crf dirtbike so those would be jetted for the crf, as for the others I would doubt they would

I have the 39mm and has had a lot of power gain, even on a stock bore, but higher compression motor. I would stay away from the edelbrok, to get the full throttle you'll have to buy an aftermarket throttle or grind your stocker out :eek:

you dont need to modify anything to run this carb, bolts up in the stock location and fits perfectly, the gas tank barely grazes this carb, which i dont think is an issue

[muff]

forgot the pics :cool:

http://www.imagestation.com/picture/sraid83/p96c7667738553232247693b2a1244dbd/fad5a896.jpg
http://www.imagestation.com/picture/sraid83/p9c0c6c004366ad6de4020e8a33670661/fad5a890.jpg

[Dave400ex]

Looks like it might not fit real well with the snorkle.

[MIKE400EX]

Hey Muff, those two little brass ports near the top and back of your carb are the vents. They should have some hose attached to them, hose will also keep most of the dirt out of the inside of the carb. Just a friendly suggestion.

[muff]

Originally posted by MIKE400EX
Hey Muff, those two little brass ports near the top and back of your carb are the vents. They should have some hose attached to them, hose will also keep most of the dirt out of the inside of the carb. Just a friendly suggestion.

thanks man, I got the carb like that and was wondering were the vents were...lol....those brass ports did catch my attention in my search but I didnt feel like just stickin tubes on my carb for no reason :p

how do you like the 41mm? I'm thinkin about upgrading

[MIKE400EX]

Muff, Keep your 39! I would have been better off with a 39 probably, but when I was looking nobody had any, only 41's. Seems to sacrifice a little bottom end torque, and I'm sure the 39 will flow plenty of air for any 400EX based motor. Just have to keep the R's up a little more. BTW, the only way you'll get the tubes to stay on those short stubs is to either wire tie, or safety wire them. Safety wire works best.

So Quadzilla doesn't think we're stealing his thread:

1. Try a 168 main, 52 pilot, idle screw 1.75 turns out, air screw in throat of carb at 2 turns out and an EMP needle in the 4th groove down from the top. That should get you pretty close.

2. Most come set up for a two cable system but work equally as well with a single pull cable.

3. As long as you order one for a 400EX then you'll get the correct size intake bell and outlet adaptor to "bolt right up". Most just barely touch the bottom of the tank - w/o any harm, like everyone said, a thin rubber strip under the tank will give it some extra room.

4. They like un-restricted air intake, so make a free-flowing lid, or if you can just remove it.

5. I havn't gotten a chance to fiddle with the Edelbrock so my opinion is a little biased, but you WILL NOT be disappointed with the FCR <<< so long as you take the time to get it dialed in correctly (not hard and more adjustable than most others).

6. Welcome to the site!

[Quadzilla]

Wow, thanks for the info guys! One more quick question: Where should I buy one from. Service Honda is selling the ones for a CRF 450 for $330. Seems like a damn good deal and this should work. If there is somebody selling those in roughly that price range known to work on a 400EX (C&D maybe?), then I'll go there... Thanks again to all. What a good group!

[MIKE400EX]

The CRF450 carb is a 40MM, not a 39. The top and cable bracket is a little taller than the "generic" 39's & 41's that are sold specifically for the 400EX. Also, I'm not sure if the adaptors on the CRF carb fit into the 400EX boots correctly. Check before you buy...maybe someone on here knows? C&D will offer you a good price, don't forget the cable.

[hawiianpwr]

Sorry Quadzilla I dont wanna mess your thread up.
But I have a question for you guys. Money wise would it be better to go with the carb before you started going into the motor? I got a 400 with K&n, open airbox, MSD ignition (Set at 10,250rpm rev limit and advanced at 4 Degrees), Dynojet kit, and a Hetrick racing pipe. My whole plan was to get everything outside of the motor before I go into it. My question is for the money should I go ahead and get the 39 fcr and finish everything outside motor wise. Or should I just go ahead and go into the motor and keep the stock carb. What do you guys think?
Thanks

[markeg192]

There's a guy that sells the39s on ebay for $399 and that is a complete kit for a 400 with jets,adapters and cable I think. All the motor buiders use the FCR and not the Edelbrock so I would do the same.

[JD400exrider]

I bought mine at C&D It came pre jetted with the billet fuel screw installed and the cable. Bolted right up. I found them to be the best price.