Engine sound rough with jetkit needles

[vmax]

Hi all,

I am just wondering (base on my hearing). Why after switch jetkit needles engine sound rough, engine sound not smooth with stock needles. Do you guys notice about this? I prove it when engine sound rough then I switch to stock needles then engine sound smooth again. I doing this just to prove it. Don't ask about performance hehehe....huge different.

[Motofool]

Originally Posted by vmax

Hi all,

I am just wondering (base on my hearing). Why after switch jetkit needles engine sound rough, engine sound not() smooth with stock needles. Do you guys notice about this? I prove it when engine sound rough then I switch to stock needles then engine sound smooth again. I doing this just to prove it. Don't ask about performance hehehe....huge different.

Is that not above a typo?
At what range of rpm's does the engine sounds rough?

[vmax]

Originally Posted by Motofool

Is that not above a typo?
At what range of rpm's does the engine sounds rough?

What is typo? I notice different sound when idle

[Motofool]

Originally Posted by vmax

What is typo? I notice different sound when idle

If the rough sound only happens when the engine is at idle, then you need to adjust the idle mix screws:
http://faq.ninja250.org/wiki/How_do_...dle_mixture%3F

[Ghostt]

How-to properly adjust idle mixture screws

Your initial setting should be 3 full turns out from the bottom, remember just slightly tighten them, don't go all Conan on them.



Then warm it up, slowly turn 1 side pilot screw in until the rpms drop, then back out till RPM's peak (and no further)* Twist throttle...see how it reacts...tweak to taste.
Repeat on other side... test ride. You're looking for best throttle response and transition from just cracked to 1/4 throttle opening or so.*

Thats a quickie, 10 cent tutorial on setting pilot screws.**