Question on this carb rebuild

M

Matt300ZXT

Member

Jun 10, 2022

#1

I'm looking at the 2 idle mixture screw/needles that came with my kit. Both are longer than the original. One has a longer threaded portion. When bottoming out the original, the needle barely pokes out through the hole while both newer ones stick out quite a bit when seated. Is there any real difference here?

Also, there is an itty bitty tiny o ring in the box....anyone know what it's for? It's not the one that goes over the accelerator pump nozzle, it's smaller than that.

Last edited: Jun 10, 2022

john sachs

Well-Known Member

Jun 10, 2022

#2

Be careful when tinkering with those screws. It's easy to destroy the diameter of the hole they poke threw. IMO, I've only seen 2 different length of the adjustment screws. If the tapers are the same, GENTLY screw either one in, and be sure it bottoms lightly. Back it out until the adjustment is right, and that there is decent thread engagement. That would be the one I would use. Small blue O-ring should go on accel pump discharge. Can't help with the smaller one, unless it belongs in the accel pump housing.
John

M

Matt300ZXT

Member

Jun 10, 2022

#3

john sachs said:
Be careful when tinkering with those screws. It's easy to destroy the diameter of the hole they poke threw. IMO, I've only seen 2 different length of the adjustment screws. If the tapers are the same, GENTLY screw either one in, and be sure it bottoms lightly. Back it out until the adjustment is right, and that there is decent thread engagement. That would be the one I would use. Small blue O-ring should go on accel pump discharge. Can't help with the smaller one, unless it belongs in the accel pump housing.
John

Yeah I figure it's something that goes to something I didn't remove. The only tiny blue o rings I saw/removed/replaced were the 2 accelerator pump ones under the cover and the one on the nozzle.

I was gentle, didn't force them in, just went until they lightly seated by hand. I'm guessing the new longer ones will work, just maybe they adjust differently since they're longer? I guess I'll find out when I get it back together and start tweaking the knobs.