Needle adjust - mid range

I have an 08 tomos sprint, biturbo exhaust, unipod filter, upjet to 58.

Once I hit about 25mph-30mph, it REALLY takes off. my low end isn't great (i have an after market sproket on the back as well to help top end) which is expected, but my mid range isn't that great.

I was reading about adjusting the needle in the carb. I tried that, I think there are 5 notches in the needle, and stock the clip is second from the bottom. I tried moving the clip up two different places, and then all the way to the bottom, and didn't feel much of a difference.

Can someone with more experience bring a little light to this situation?


Re: Needle adjust - mid range


Re: Needle adjust - mid range

the needle setting effects the richness of your mixture between 1/4 and 3/4 throttle. by raising the clip, you lower the needle, which allows less fuel into your mix across that range - or vice versa.

to tune your needle setting, try this: idle the bike on its stand until it's warmed up. then, open the throttle up to a 1/4 or a little more. if the engine bogs (i.e., slows down for a second, before picking back up, and sounds kind of wet/gargly) then your needle setting is too rich: raise the clip, lower the needle. if it doesn't bog, lower the clip, raise the needle. basically, you want the needle at the highest setting that doesn't bog.

note that your idle should be tuned to exactly where you want it before you start this process. also, if your carb has an air screw, this process doesn't apply, since you're going to have to fuck with that too. also, you should tune your main jet first with wot runs and plug chops before fucking with your needle.

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