torque and responsiveness

15 replies to this topic
  • Ranger18

Posted February 21, 2006 - 09:56 AM


hi, im wondering what i can do to make my 2001 yz426 make a lot more torque and responsivness so i can rip on the track, oh and im not looking on spending a bundle on cash either, so if anyone knows what i should do for fairly cheap, please let me know, thanks

  • ESC

Posted February 21, 2006 - 09:58 AM


Look for the BK mod here on the forums. It will eliminate the off-idle bog.

  • kizzle426

Posted February 21, 2006 - 10:02 AM


BK mod and the light blue mod (easier starting, eliminates fowling). Here's the website for those mods. Click on tech articles. (RIP, Motoman)

  • Ranger18

Posted February 22, 2006 - 10:35 AM


thanks to both of you, i think im going to do it for sure, but the website that describes how to do it, is kind of vague to me, if you dont mind, could one of you in detail explain exactly how to do it and what kind of springs i should get, because im not one who likes to take risks with a carb. thanks a lot.
if you could give me the exact size screws you also used, thanks.

  • kid on a 426

Posted February 23, 2006 - 05:56 PM


you could try a power now and rejet it

  • idiot_on_426

Posted February 23, 2006 - 06:46 PM


could you explain to me what a power now is please?

  • RCannon

Posted February 23, 2006 - 07:17 PM


If you need more power than the 426 has, give yamaha a call. If you can demonstrate the ability, count on walking out of there a millionaire with free bikes.

Honestly now, which area do you find lacking in that 50 hp bike?

Not wanting to sound like an ass. Please dont take it that way. Suspension mods will give you much better track performance than messing with a damn near perfect motor. The forks can use some work. The rear shock is liveable.

Practice, Practice, and practice more. You will then win races.

Add ten hp to your bike? You'll finish about where you finish now.

  • idiot_on_426

Posted February 23, 2006 - 07:28 PM


i actually do have very nice provalve suspension set to my weight, but thanks, i rode my friends 450 and it just seemed nicer to have a little more snap in the throttle and thats all im looking for. oh and im the same guy as ranger18 one th previous message, i just made my own membership

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  • flintlock28

Posted February 23, 2006 - 07:43 PM


One quick question.....

Are you using an adjustable Fuel Screw???

Just by altering the Fuel screw a little bit to optimize the carb mixture (temperature, humidity, altitude) can make a big difference from off idle to midrange on how the bike pulls. If my bike is running too rich for the day I'm riding, it won't pull the front wheel up like normal......however, if I adjust the Fuel Screw to it's optimum setting for the conditions...viola! the front wheel is coming up again just fine.

If you don't have an aftermarket adjustable Fuel Scrww, than get one.

  • 642MX

Posted February 23, 2006 - 08:37 PM


1. Wiseco 13.5:1 piston. Lots of off idle snap, it makes a huge difference in the mid range also.

2. Boyesen Quick Shot. Simple bolt on, 3 screws and your done. No more bog.

3. JD Jet Kit. Awesome throttle response, easier starting, more mid range pull.

  • River4Life

Posted February 23, 2006 - 09:31 PM


try not riding it like a puss

  • idiot_on_426

Posted February 24, 2006 - 07:01 AM


hey thanks ill look into doing that man.

  • idiot_on_426

Posted February 24, 2006 - 07:02 AM


i think ill pass on changing the piston cause its too much cash, but ill look into the other things. thanks man

  • idiot_on_426

Posted March 06, 2006 - 10:35 AM


hey i did the BK mod and i rode at glamis and it seemed like my bike wasnt running good and the power was slipping and it was harder to start, what do you think, what do i need to adjust

  • kid on a 426

Posted March 06, 2006 - 04:24 PM


you could try a power now and rejet it

Also a adjustable fuel screw a quick shot and maybe a more free flowing pipe if you want to spend that much money. You could maybe go up a tooth or two in the back and maybe an aluminum sprocket or an iron man because they're so light it will snap better

  • cowboyona426

Posted March 06, 2006 - 07:31 PM


IMO, don't waste your money on the PowerNow. Use about the same amount of cash and get an 03 YZ 450F exhaust cam, hands down the best $100 you'll spend on a 426. If you have the coin and the need, I'd also look into a Thunder Alley pipe.

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