A few mods. for the fun of it........

[Kirklandrock]

My father in law has an 01 TRX 400EX, he is a bit of a motor head and has asked me to help him put together a few mods. to give the ol' girl a little more ***.....:devil

let me know what this list of mods sounds like... as far as performance gains...... I dont care what it SOUNDS like....


Std. Bore JE piston (10:5.1 or 10:8.1) comp.ratio
XR cam (which I understand is a "Drop In")
K+N power Up kit ( which I understand comes with jets etc...)
Mods to the airbox lid (probably the 1" holes thing 6-8 holes)

Here is where I am miffed..... I have considered modding the head pipe ( grinding the weld etc.) and adding an FMF PC IV sa
slip-on.......

My Second consideration was the FMF PowerBong (as Rico says)
and the PC IV sa.......

Let me know what you guys think about my Exhaust Dilema

he uses it to trail ride..... but I hit the occasional Hare Scramble on it...... he he

[barbwire44]

Sounds like great mods i have the same setup other than i went 406 (86mm) on the piston, as far as the pipe i love the powercore IV-2 it adds gobbs of torque. The stock headpipe seems fine ive only rode one powerbomb wich i think i will add this winter. And i dont like k&n filters for trail riding or hare scrambles they dont perform well with water and dust, I think i would buy the uni filter and uni vents. I would guess you should gain around 5-8 horse with that setup.

[Kirklandrock]

Thanks for the advice on the K+N... I used them on my 3-wheelers in the 80's with good success. but I have heard more than one person say that they didnt like the K+N in the dust....

I think I will research the Uni, or maybe the White Powerfilter..
I will also use the Uni-vents in the lid.... I think white bros. even makes those vents also....... Or Uni. makes them for White Bros. or something.........


Thanks Again...........:)

[barbwire44]

Ya its just personal preference on the k&n but from what i have seen i dont like em. I rebuilt a quadracer last night well just rerung it and put a new stator in and it had a k&n in it and the intake side of the piston looked like it had been hit with a sandblaster, but the kid didnt want to buy a new piston so we just put it back in, but after showing him the piston he did agree and put the stock filter back on.:D

If money is not and issue get a Curtis Sparks X-6 505-563 shipped that will give it more "xxx" especilly and none arrested one. If you have a lot of cash on hand I also recommend the Keihin FCR carb 460 shipped. If not the Jet kit will still make a noticeable difference and make the machine a lot more fun.

[oynot400]

I just added the Power Bong (as Rico says) and I already had the Power Core IV 2 SA. It really does quite it down and from what I can tell it adds more power. I can't say for sure because I added a FCR carb at the same time. Which I am still dialing it in, I am almost go it. So I can't say how much it added but it was a good combo.
The nice thing with FMF, they are great to work with. If you ever have a problem they are alway happy to help out. Heck they replaced my SA after I already had it a year. :cool: