Which is better 04/05 carb 0r 06+ carb?

mykids · 06-11-2010, 01:48 PM

What size is the 04/05 carb and what size is the 06+ carb? Which one is better?

Baileygunns · 06-11-2010, 03:04 PM

Bore the 06+ carb and it has better acceleration.

dyechainsaw · 06-11-2010, 03:35 PM

04/05 42mm
06+ 40mm

mykids · 06-11-2010, 04:37 PM

Thanks for the help baileygunns and dyechainsaw.

711racer · 07-31-2011, 10:34 PM

I have a question about 05/06 carbs as well.
I have an mx 05 trx450r w/ 13.5.1 sparks piston, sparks exhaust, stage 2 hot cam, and I swapped out the 05 for the 06 carb that was on the first bike(06 that was having problems)
My questions is if I swapped back to an 05 carb, how much if any difference would there be in performance?
The only reason I'm thinking of doing this is I have two bad wrists(broke them when I was younger) and get terrible arm pump within 3-5 min of riding. I let a friend of mine borrow my 06 carb to go to a national race as his started sticking the day before he left... and he says it was all he could do to hold on after a few laps and he never gets arm pump.
This is what I think maybe a last resort as I've tried everything I can think of from working out my hands and wrist to spending stupid amounts of money trying to get my ike better setup... any help would be great. Thanks.

StonedInNy · 08-01-2011, 01:08 PM

performance wise the the FCR carbs (06+) have a better throttle response than the keihn (04/05) carb . As far as your wrist issue there is a link in this section on how to make the fcr carb easier on the thumb bye modding the spring. A good antivibe stem and som flex bars will help you alot too.

Was in Engine tech faq section
FCR Throttle Spring Mod

Kyrider · 08-03-2011, 03:29 PM

i put a fcr on my 04 and the throttle response was better but it killed my power so i switched back to my stock 04 carb

Alex90 · 08-03-2011, 03:43 PM

alot of the GNCC guys swap to the older 04/05 carb.. i assume for the low end power gains? dont quote me

tm85478 · 08-03-2011, 09:44 PM

Kyrider - How much power did you lose? Do you think boring the stock 04 carb show an improvement?

Kyrider · 08-03-2011, 10:44 PM

my et times in drag went from a 3.8 to a 4.2-4.3 when i switched to the fcr carb, i think if you bored the fcr out it would be wayyy better than the stock carb

airmobile101 · 08-03-2011, 10:49 PM

I feel the FCR is better. People say they are harder to work on, or they need constant tuning. I disagree with any of that. But..... it all depends on your build and what you race.

06-11-2010, 03:35 PM	#3 (permalink)
dyechainsaw 300EX Rider Join Date: Jan 2009 Location: Rapid River, MI Posts: 586	04/05 42mm 06+ 40mm __________________ 2004 #10 Flattrack Trx450r - Racers Edge 62/38 SS/SB 2012 AMA District 14 "A" class State Champion 2012 WLR 0-450 studded Series Champ

08-01-2011, 01:08 PM	#6 (permalink)
StonedInNy 300EX Rider Join Date: Jan 2008 Location: East Quogue New York Posts: 916	performance wise the the FCR carbs (06+) have a better throttle response than the keihn (04/05) carb . As far as your wrist issue there is a link in this section on how to make the fcr carb easier on the thumb bye modding the spring. A good antivibe stem and som flex bars will help you alot too. Was in Engine tech faq section FCR Throttle Spring Mod __________________ 04 trx 471r My Youtube vids checkem out. http://www.youtube.com/user/jdellav73?feature=mhee Last edited by StonedInNy; 08-01-2011 at 01:11 PM.

08-03-2011, 03:29 PM	#7 (permalink)
Kyrider 250EX Rider Join Date: Sep 2010 Posts: 492	i put a fcr on my 04 and the throttle response was better but it killed my power so i switched back to my stock 04 carb __________________ 04 450R RACERS EDGE POWERED 64/36 SB/SS

08-03-2011, 03:43 PM	#8 (permalink)
Alex90 300EX Rider Join Date: Apr 2011 Location: hair dryer in the face, Arizona Posts: 550	alot of the GNCC guys swap to the older 04/05 carb.. i assume for the low end power gains? dont quote me __________________

08-03-2011, 09:44 PM	#9 (permalink)
tm85478 TRX90 Rider Join Date: Jul 2009 Location: Illinois / Michigan Posts: 39	Kyrider - How much power did you lose? Do you think boring the stock 04 carb show an improvement? __________________ 05 TRX 450R 12.25 Venom piston HRC kit White Brothers Aluminum Pro Pipe 13/38 Gearing

06-11-2010, 01:48 PM	#1 (permalink)
mykids TRX90 Rider Join Date: Jun 2010 Posts: 29	What size is the 04/05 carb and what size is the 06+ carb? Which one is better?

06-11-2010, 03:04 PM	#2 (permalink)
Baileygunns Super Moderator Join Date: Nov 2009 Location: New Hampshire Posts: 2,849	Bore the 06+ carb and it has better acceleration.

06-11-2010, 04:37 PM	#4 (permalink)
mykids TRX90 Rider Join Date: Jun 2010 Posts: 29	Thanks for the help baileygunns and dyechainsaw.

07-31-2011, 10:34 PM	#5 (permalink)
711racer TRX90 Rider Join Date: Apr 2010 Posts: 15	I have a question about 05/06 carbs as well. I have an mx 05 trx450r w/ 13.5.1 sparks piston, sparks exhaust, stage 2 hot cam, and I swapped out the 05 for the 06 carb that was on the first bike(06 that was having problems) My questions is if I swapped back to an 05 carb, how much if any difference would there be in performance? The only reason I'm thinking of doing this is I have two bad wrists(broke them when I was younger) and get terrible arm pump within 3-5 min of riding. I let a friend of mine borrow my 06 carb to go to a national race as his started sticking the day before he left... and he says it was all he could do to hold on after a few laps and he never gets arm pump. This is what I think maybe a last resort as I've tried everything I can think of from working out my hands and wrist to spending stupid amounts of money trying to get my ike better setup... any help would be great. Thanks.

08-03-2011, 10:44 PM	#10 (permalink)
Kyrider 250EX Rider Join Date: Sep 2010 Posts: 492	my et times in drag went from a 3.8 to a 4.2-4.3 when i switched to the fcr carb, i think if you bored the fcr out it would be wayyy better than the stock carb __________________ 04 450R RACERS EDGE POWERED 64/36 SB/SS

08-03-2011, 10:49 PM	#11 (permalink)
airmobile101 bannedatatvnews.net Join Date: Oct 2009 Location: Hillsboro,MO Posts: 1,391	I feel the FCR is better. People say they are harder to work on, or they need constant tuning. I disagree with any of that. But..... it all depends on your build and what you race. __________________

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