FMF Q pipe blues.

Well I finally decided to quiet my bike and bought an FMF Q and power bomb. I changed my jets and have been messing with my Fuel screw but it just wont run right. I have a 2001 YZ 426 that now has a power band like my old KX 500. Super bog then throw you on your lid burst of power. I am really dissapoited. $500.00+ dollars and it runs so bad I am thinking of just putting the E series back on and selling the thing. Please let me know you ideas or make me an offer on buying it. I ride at Carnegie so need the quiet so the rangers will leave me alone. :)

The "Q" pipe will take some power from your bike even when it's jetted correctly, as will any other solution to get your bike in compliance with sound regulations. You'll just have to live with it.

I've been running the "Q" pipes since they hit the ground about four years ago. Back in '01 when I put the pipe on my 426 I soon found it too run like crappola. I then took it up to a place I frequent for riding and spent the day messing with the carb to get it running the best I could. Here's what I found to work the best:

Dropped the main jet one size from stock.

Dropped the pilot jet one size from stock.

Dropped the needle two clip positions (means I put the clip two positions higher than it was).

Left the fuel mixture screw at one and half turns out.

This is also how my dual-sported '02 YZ426 is currently configured. Good luck.

Hey dude i have your same exact setup 01 YZ426 Power Bomb and the Q muffler, my bike runs great there is no two stroke power band like your explaining with yours, it starts right up, runs smooth, no bogging at any RPM, i am not sure right off hand what jets i ran but i will look into it and get back to you. By the way i have raced that harescramble there in livermore a few times on this bike with that same setup, so i am jetted for the elevation.


Hey any info is most appreciated. I love my 426 but am just so bummed right now I cannot even tell you. I am currently running the stock size jets again. I started with a 168 main and a 42 pilot. I am going to take apart my carb to see my needle setting. Have you done this before? Is it a big deal? How bout the JD jet kit?

Try posting this on the jetting forum area.

Thanks I also posted on the jetting forum. :)

Hey, i am not sure what is the difference between the q muffler and the pwoercore 1v spark arrestor? i have an '01 426 with powerbomb header and iv2 spark arrestor, what is different from the q? by the way carnegie is great, ever heard of scott burns? pro hill cimber. and how much would it take for you to part ways with your e series exhaust system. please let me know iam very interested.

How about $90?

$90? is this just for the muffler or the whole system? i sent you a private message reply to it when you can, i am very interested, thankyou

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