PDA

View Full Version : What Carb for an '04 TRX450r ?


reptikes
08-07-2007, 01:37 PM
I was wondering what is a good Carb to put on a 2004 T-REX 450r? And would i have to get different jets for certian types of Carbs? I have HRC jets right now.

Thanks,
Mike
MR.BIG
08-07-2007, 02:42 PM
I would go with a 41mm FCR carb they make a huge improvement over stock.
450R_lover
08-07-2007, 03:44 PM
Right now, if your low on money you could go with a 40mm fcr off of a crf450. Then later when you get some more cash you can have it bored out to like a 42 or 43... I say this because those 41mm fcr mx carbs are expensive. I got my 40mm fcr for 260. the 41mm are like 5-600. jmho
reptikes
08-07-2007, 05:03 PM
What is 41mm FCR ? Who makes it?
450R_lover
08-07-2007, 06:02 PM
Keihin makes the carb.
patrickj75
08-08-2007, 08:18 AM
i just bought an 07 crf carb from Service Honda for $395 and then had it taper bored by Chad at DRG. makes a big difference.
chad502ex
08-09-2007, 01:25 PM
Originally posted by patrickj75
i just bought an 07 crf carb from Service Honda for $395 and then had it taper bored by Chad at DRG. makes a big difference.

Thank you for your shout out!

here's my flow test on the same type of FCR carb as yours ;)
pro-rider46
08-09-2007, 01:52 PM
i think i will do that soon in the future


i liked the way the chart looks over stock. hey chad can you tell me the benifits of a taper bore over straight bore, i know that smaller carbs give more torque and larger carbs give more horsepower, is the taper bore kinda like both of both worlds
chad502ex
08-09-2007, 02:12 PM
Originally posted by pro-rider46
i think i will do that soon in the future


i liked the way the chart looks over stock. hey chad can you tell me the benifits of a taper bore over straight bore, i know that smaller carbs give more torque and larger carbs give more horsepower, is the taper bore kinda like both of both worlds

exactly!

a taper bore carb is precisely angle bored to provide a larger cross sectional area at the carbs center venturi for top end power with the bore angle assisting to increase the velocity loss with boring for low end performance.

The taper is meant to increase velocity through the carb, whereas a straight bore carb only increases cross-sectional area and actually decreased the velocity through it.

taper bore = velocity and cross-sectional increase

straight bore = velocity decrease with cross-sectional increase
Macadoo355
08-11-2007, 03:43 PM
I had a 41mm fcr on my 400ex and hated it, now im going to try it out on my 450 and see how it does.