Carb. YFZ or TRX

[jeremyblake924]

I have a 400ex with 440kit, 11:1 comp, minor port work, hmf pipe(no baffle), k&n filter, and stage 3 hotcam. Which is better for performance,YFZ450 or TRX450R carb? It dont matter how hard it is to install. I just want the best performance of the two, with a clean look. Any help is GREATLY appreciated!!Thanks.

[jman7290]

First thing first, get rid of the K&N filter!!! I hear good things about the 450R carb and a member on here makes a nice adapter out of billet that makes it bolt up nice. I got a sorta like a future hot rod bike that I am slowly building starting with a bare Lonestar frame and subframe. I have been thinking about putting the 450R carb on my 440 and my Edelbrock on the future project bike that should be finished when my 3, and 6 year olds graduate college!!,

[jeremyblake924]

I've heard alot of bad about k&n also. I'm also running an outerwears cover for now with uni already ordered! Thanks

[CJM]

450R carb will be much easier to install and tune but the yfz fcr carb will make more power. Probably 1-2hp more than the R carb.

Your choice but imho the 450r carb is easier to tune which is a big deal to me.

[DragonGunner]

Isn't the 450R carb a much smoother and easy on the thumb compared to the yfz? I've always heard the YFZ carb is very stiff on the thumb throttle....

[DragonGunner]

Originally posted by jeremyblake924
I've heard alot of bad about k&n also. I'm also running an outerwears cover for now with uni already ordered! Thanks


Not from me you didn't......LOL.

[400man]

Originally posted by DragonGunner
Isn't the 450R carb a much smoother and easy on the thumb compared to the yfz? I've always heard the YFZ carb is very stiff on the thumb throttle....

when I installed my yfz carb the thumb throttle felt alot easier and lighter than the stock 400ex carb. it did take some time getting everything to fit right and a few trips to the hard ware store for some rubber plumbing couplers. I have a old topic on here from where I first put it on with alot of pics. I havent really messed with jetting much except from when I first put the carb on, and I also did the "zip tie" trick to fix the bog and hesitation when you punch the gas.

http://i417.photobucket.com/albums/pp255/ky2stroker/400ex450r008.jpg

http://i417.photobucket.com/albums/pp255/ky2stroker/400ex450r009.jpg

[JOHNDOE83]

I highly reccommend the 42mm 05 450r carb.

Regardless of carb style, you wont see any extra HP unless you get a minnimum of 40mm carb.

The 42mm 450r carb is better then any 38 or 39mm carb for more HP.

If you got a fcr style carb it would need to be atleast 40mm to see good improvement over the 42mm 450r carb.

[riotact]

400man could you point me in the direction to your thread of the install.I wouldn't mind checking it out.I tried to search for it but came up empty handed.

[Blodg]

Originally posted by 400man
I havent really messed with jetting much except from when I first put the carb on, and I also did the "zip tie" trick to fix the bog and hesitation when you punch the gas.

I have read most of the old threads on here about the 450R carbs but do not know what the "zip tie trick" is?

[CJM]

Originally posted by Blodg
I have read most of the old threads on here about the 450R carbs but do not know what the "zip tie trick" is?

That doesnt apply to the 04-05 450r carbs, it applies to fcr carbs.

[Blodg]

Originally posted by CJM
That doesnt apply to the 04-05 450r carbs, it applies to fcr carbs.
Yes I am aware of that (although it may have appeared that I was not with my comment about reading all the 450R carb threads which did apply to the 04-05). Anyways, I have a 39mm FCR on the 492cc 350X motor in my hybrid so that is why I was asking.

[400man]

A friend of mine who works at a bike shop showed me the zip tie trick when i told him i had a yfz carb an hard trouble with a hesitation when i hit the gas. it has to do with the accelator pump and the little arm/mechanism that works it.

[400man]

here we go, I guess I never made a topic of my own but I ended up posting in someone elses with my pics,

http://www.exriders.com/vbb/showthread.php?s=&threadid=460141&perpage=10&pagenumber=1

[riotact]

Thanks!!

[Blodg]

Thanks for going back and finding the old thread 400man. I still didn't see any explanation of the zip-tie trick but that is OK, I don't have a problem with bog or hesitation with my FCR.