Why did Honda Change Carb Size IN 06 model

[smitey187]

I have a 05 trx 450r and i wad wondering why did honda change carb size to a smaller one in the 06 model and change TPS sensor????

[4ABURN]

The FCR carb flows better and has better throttle response and makes more power, even if it is alittle smaller than 04,05. alittle more tunable also. hope this helps.:D :D

[compedge]

a smaller carb will also give it a little more botton end and less top end. its a Keihin 40.0mm flat slide on the 06. On the street bikes I build the Keihin gives a bike better throttle response. and quicker aceleration.

[lafinrat]

they may have changed the venturi size, but I believe a 40 FCR outflows a 42 butterfly carb. the butterfly in the 04-05 carb would reduce flow because it takes up surface area. the FCR is just a wide open hole when you open it up--except the needle of course.

[chad502ex]

the stock 04 venturi is 39mm

so 42 to 39mm butterfly throttle body

anyone put an 06 carb on their 04/05?

[cals400ex]

it is easier to put a crf 450 FCR 40mm on the 04-05 bikes than the 06 FCR.

[jeepnrocks]

went to an fcr. i believe its a more efficient carb

[compedge]

Originally posted by cals400ex
it is easier to put a crf 450 FCR 40mm on the 04-05 bikes than the 06 FCR.

Can you still use the thumbe throttle or do you havve to use a twist throttle