OFNA uses the same pic for multipole cars and engines.. I'm sure there are at least one Force engine that has a Mid needle.. As a rule, you don't wanna mess with the mid needle in off-road anyway..

ok so what should i set the mid needle at. i adjust it buy accident.

so the other needle will be idle? so my motor has no LSN?

The Force .28 engines i have seen didn't have a midrange needle.
Just a LSN (D in the picture) and a HSN (A in the picture)and ofcourse idle screw (C in the picture).

D or B? i think u got the letters mixed up .... any mine does have the LSN (B) in the pic.... But yet i have the D adjustment...

(im looking at the first 2 pics on that site..)

Weird, haven't seen a Force .28 with midrange (B) needle before...maybe it's an older (or newer) version.

Normally it has a LSN (D)
HSN (A)
and idle screw (C)

The location of the B needle would suggest it is a midrange needle. Usually they are best left alone unless you know what your doing. For tuning you use the LSN for engine pic up and low revs and HSN for full throttle setting. Idle screw is for setting the idle gap (usually between 0.5 and 1mm)

heres some pics of mine... im confused now

Wantboost, you do not have a midneedle.. You have a standard 2 needle carb.. the 3rd "needle" is most likely your idle screw..

A Hyper Mach 28 has the 3 needle carb...it is another OFNA 28...the Force 28 is a 2 needle carb unless someone swapped on another carb

so 2 needle being HSN and LSN?

Yes, in your picture i see the LSN in the sliding carb barrel (where the throttle linkage connects to the carb slide) and i see a HSN (the fuel line connects to it) + idle screw.
You have no midrange needle.

so did someone change teh carb on me? How do i know the LSN is at flush on mine?

help................

No one changed the carb on you.. Like I said before OFNA uses generic pics for their paper work.. 2 needle carbs are much easier to tune anyway.

How do you know it is at flush?? You back it out until it is flush with the linkage attachment. Linkage attachment is where you connect the servo to the carb.. You will need to back out the HSN too, which is where the fuel line attachs..

Once you get both backed out.. Set your idle gap to around 1mm (About the thickness of a credit card). Lean the bottom end out until the engine continues to idle with out dieing.. The idle will be low, but that is okay.. Now throw it on the track and run it around some, 4-5 laps at least.. Top end should be none existent.. Once you get 4-5 laps in bring it in and lean the top 1 hour.. Think of the hour hand on a clock, and how far it moves from 12-1 or 1-2, etc.. Then take another lap. Bring in and lean 1 more hour, and repeat this until the engine shows no lag in performance, ie revs nicelt from bottom to the top, and seems to run out of speed at teh end fo the straight. When you reach that point, richen the HSN 1 hour, and reset your Idle like I explained before.. 1mm gap, should not have moved, but the idle may be a bit high now rich to lower..

If there is anybody at the track, ask them for some help, and ask questions.. Good Luck..


PS: if you are doing trying to tune in the street, your engine will most likeley end up tuned very lean.. So, set a distance that you will use for your "Straight Away", and do not try to lean your engine to continue revving for half a city block.. I would say 100ft or 30meters would be about the max distance you want to go.. Keep adjustments small, and only one needle at a time.. Keep fuel tank around half full for best over all tune.

hmm this is the only part i am unsure of. i will give it a shot

The place I have circled in red is the needle I am refering to.. Back it out until it is flush with the carb slide..