FCR on 04/05 engine

[K-Dub]

What FCR does the 04/05 450R use to make the switch? Any year CRF450R FCR? What else do you have to do to make it fit? Is the FCR bigger than the stock 04/05 carb?

Thanks for the help.

[eagertorace]

Originally posted by K-Dub
What FCR does the 04/05 450R use to make the switch? Any year CRF450R FCR? What else do you have to do to make it fit? Is the FCR bigger than the stock 04/05 carb?

Thanks for the help.

It's smaller. You can get the trx fcr with matching airbox. The 05 intake will fit but it's very tight

[turbo j]

This is an excellent mod for the 05. You can either buy the 06+ airbox and boot or a billet adaptor from Noss or Janssen and use the 05 intake system. I prefer the adaptor method because I think the 06 box cranks on the rear suspension easier. The 06 box has a considerably bigger air filter though.

[K-Dub]

Thanks for the answers. Is there any difference between 40mm FCRs? I found a new one that says it will work with the TRX and YFZ. It states it is set up for single cable use, will this one work? What throttle cable do I use? 06 newer?

[ghott]

Flatslide (FCR) carbs are far superior to the 04/05 TRX's butterfly style carb.

All CRF450R FCR carbs will work from 02 - 08...the newer, the better...all are 40mm. YFZ450 carbs will work as well, they are all 39mm. All can be bored out to 43-44mm by places like SREDRUM and Racers Edge AZ.

06+ TRX450ER carbs will work, but are too tall to clear the 04/05 gas tanks...you either have to cut the top of the carb off, heat and mold the bottom of the 04/05 gas tank, or buy an 06+ gas tank to use.

All of these carbs will work with 04/05 stock intake boot as long as you get a NOSS or DASA FCR adapter. You could also just get an 06+ intake and use the carb without the adapter. I prefer the 04/05 intake and NOSS/DASA adapter option.

Check out the site in my sig if you want to see some pictures of a bored FCR with adapter on an 04/05 bike.

[D Bergstrom]

Originally posted by ghott

All CRF450R FCR carbs will work from 02 - 08...the newer, the better...all are 40mm.

Ghott's post has lots of great info, the only thing I will add is the 07 and 08 CRF carbs are 41mm.

An FCR carb was one if the last mods I installed on my 450R's, it should have been one of the first. The increased throttle response is incrediable.

Doug

[ghott]

Originally posted by D Bergstrom
Ghott's post has lots of great info, the only thing I will add is the 07 and 08 CRF carbs are 41mm.

An FCR carb was one if the last mods I installed on my 450R's, it should have been one of the first. The increased throttle response is incrediable.

Doug

Thanks Doug, you're absolutely correct. The '07 and '08 CRF450R carbs are indeed 41mm and have an updated accelerator pump that helps a lot with the off-idle bog.

[K-Dub]

Thank you both. Ghott I am checking out your link now.
I am looking at a 40mm FCR without hot start. Now in 8 years of owning my 04 I have never used my hotstart to the point it was unhooked for the last 6 years, so I am not worrying about not having it. It is brand new and has a Powershot pump and Billet Fuel Screw and is set up for a single throttle cable. The TPS has CRF plug and I already have the wiring diagram to change it over I believe.
Pink = Blue
Light Grn = Yellow
Grn/Ylw = Black

SO this FCR should work, from what I am reading?

[fastredrider44]

I can't remember the wire colors, but all that sounds correct. I will say that I like having the hotstart. I have a trx FCR on my current bike and it is definately too tall, but I made it work. I then put an FCR on my friends bike from an 06 CRF and everything cleared just fine. We both ran 06 airboxes with risers and no lids, and we also used the 06 up head to carb boot.

[K-Dub]

Will the 05 head to carb boot not work? Here is the one I bought FCR 40mm (http://www.ebay.com/itm/290795596172?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649)
Hope it is one that will work.

Thank you guys for all the info.

[levi624]

I wouldn't mess around with everything you have to modify for just any fcr carb. Sparks makes a 41 fcr that bolts right on no mods of any kind. I run one and it makes a huge difference.

[njquadracer11]

yea but the sparks is also ridiculously over priced

[njquadracer11]

i rather buy a used one for half the price and jet it myself, just my opinion though and i have an 05 with an fcr

[levi624]

It's more then just jetting. It's how it lines up with the intake on both the motor and filter sides. Plus the adapters needed and it still isn't a straight shot like the stock boots. Also the throttle cable and tps sensor.

[DnB_racing]

Originally posted by K-Dub
I already have the wiring diagram to change it over I believe.
Pink = Blue
Light Grn = Yellow
Grn/Ylw = Black

your spot on!!!! this is the wire color code,

and im sure you have figured out how to reuse your old existing connector plastic body, buy removing the pins and reinstalling in your connector body ...

its actually a simple change well worth doing this way instead of paying a ridiculously high price like a sparks,

i cant imagine why anyone would spend that much for a simple modification that can be done by just about anyone with a little know how:confused:

[CJM]

Originally posted by njquadracer11
yea but the sparks is also ridiculously over priced

For the money, even if you bought the carb and had to totally rebuild and get the adapters its still cheaper than the sparks.

[levi624]

I want to know where your buying your carbs from so I can buy a few? I work at a Honda dealer and cost is only a 150 cheaper then the sparks.

[CJM]

Originally posted by levi624
I want to know where your buying your carbs from so I can buy a few? I work at a Honda dealer and cost is only a 150 cheaper then the sparks.

Ebay, forums, etc. Who in their right mind would buy new? An FCR used is about 150-250 depending on if the person knows what they got. Even if you gotta rebuild it your still cheaper than sparks.

Dealers outrageous for parts it seems in almost all cases.

Plus, I just looked it up-sparks wants a grand for an fcr they modified...wtf?? :eek2:

[njquadracer11]

^^^i second that

[2001400exrida]

seriously you can have an FCR carb hooked up for $200 or less.

yfz carbs, crf carbs, or the trx carbs which require the most modding.

I put a crf carb on mine with an adaptor. I simply unplugged the tps, cut the wires at the throttle and it runs like a champ.

[DnB_racing]

Originally posted by 2001400exrida
seriously you can have an FCR carb hooked up for $200 or less.

yfz carbs, crf carbs, or the trx carbs which require the most modding.

I put a crf carb on mine with an adaptor. I simply unplugged the tps, cut the wires at the throttle and it runs like a champ. I agree the TPS is unnecessary unless your running an aftermarket ignition..

the stock doesnt have actual maps, just resistors and capacitors to discharge at rev limit, no means to adjust timing

[K-Dub]

The FCR I bought off ebay showed up today. It is brand spanking new. $360 to the door, I checked the Honda price and got scared. lol Now to decide if I want to buy the adapter or an 06 set up. The carb is set up to hook the PCV hose on it. So I will be able to stop running that hose to the air box.

[d3ktrix]

Everyone that I ever talked to with a dyno preferred the NOSS adapter with an 05 intake over the 06 intake.
Plus the 06 airbox fits like crap in the 05 subframe.

DRG advised me to go with the 05 intake on my 07 CRF carb.
Most Rage/Dasa 05 builds that I have seen with FCRs use the 05 intake.

[K-Dub]

Thank you for the info, I will look into that.