carb diaphram needle settings

[luc8421]

Hey guys, I've got a quick carb question. I took my diaphram completely apart, and I noticed on the long needle there are different settings for the position of the e-clip, to adjust the length of the needle. What does this affect, and is it only for when you change the size of the main jets.

[Anonymous]

Re: carb diaphram needle settings

Hey guys, I've got a quick carb question. I took my diaphram completely apart, and I noticed on the long needle there are different settings for the position of the e-clip, to adjust the length of the needle. What does this affect, and is it only for when you change the size of the main jets.

This adjusts the amount of fuel from the float bowl in your mid-range (1/4 to 3/4 throttle). The lower the needle sits, the leaner the mixture, the higher it sits, the richer the mixture. If the bike is running well right now, leave it alone. If you're adding a K&N filter and/or 4 into 1, you may want to raise the needle a notch.

[Anonymous]

What do ya'll think?

I finally got my idle setting down I believe. She idles nicely but I haven't checked plugs. Anyways, I had the needles set at 3 notches down from the top and had a pretty bad lean at full throttle, so I dropped the shim one more notch and have really good exceleration at mid range rpms, say 30-50 mph but she feels slow at full throttle. One more shim size you think? That would put me at 5 notches from the top, seems a bit much!!!

I am running MAC 4-1, K&N pods, stg 3 jet kit, Accel coils w/ .035 gap on plugs. (Before adjusting the needles, I was at 3 notches and she accelerated fine up this big hill by my house, now I could not get her to pull past 70mph this morning.)

Thx,

[Detman101]

thank you for making this thread. I have the same symptoms of a weak mid-range but wide open is like a rocket. This is after adjusting to smaller (proper) main jets.
I will raise my needles a notch and fix it.

Thakns,
Dm of mD

[Anonymous]

aschessla the needle is only for midrange, the main jet is for full throttle.

[Anonymous]

I am running the larger main jet, 155 I believe, should I drop it to the 150? Could it be bogging due to overly rich? Will dropping the main jet affect my idle?

Thx

[Anonymous]

I am running the larger main jet, 155 I believe, should I drop it to the 150? Could it be bogging due to overly rich? Will dropping the main jet affect my idle?

Thx

Dropping the main won't affect your idle. What year and size of bike do you have? Are these Mikuni main jets you have or Dynojet jets?

[Anonymous]

Read the plugs

You'll also need to read your plugs to knwo what to do. Take the bike out and open up the throttle to 3/4 to full. Then coast to a stop. DO not donwshift or use the engine to slow you down. Pull the plugs and read them are they lean or rich?

You can test your mid range as well this way. Bring the throttle up to 1/3 to 3/4 then coast to a stop (you can use brakes, just don't use the engine to stop)

[Anonymous]

I have an '81 GS550T and the Dynojet kit, stg 3.

I am running the larger main jet, 155 I believe, should I drop it to the 150? Could it be bogging due to overly rich? Will dropping the main jet affect my idle?

Thx

Dropping the main won't affect your idle. What year and size of bike do you have? Are these Mikuni main jets you have or Dynojet jets?