I am attmepting to tune a stock carb for a 12A stret port.

The Chilton's manual said that there are two adjustments screws on the carb facing the left side of the car.

Here is the problem. I see only 1 screw whichs acts like it is the Mixture screw.

Where in the **** is the idle screw!?!?! Useing a o2 monitor I've got the car to run much better but I need to adjust the idle in order to set timing, etc.

Looking at the picture in the Chilton's manual the idle screw is supposed to be above the mixture. I only see a embpty vacuum line hole there.

It is not a california model.

Can anyone help??


Thanks,

Thomas

 

I cant get to my cardomain site to post the pics. DO a search, I answered that exact question a while back, with pics. The one screw you see is the mixture, the idle speed is to the right of the accelerator pump cover. Its kinda hidden in the linkage.

 

Chiltons sucks. Get a Heynes Manual!

And if you feel like splurging you can get a factory shop manual, but I've done alright without it.

Carl's the man, he's the carb expert Yeah, it's hidden in there, you have to get your head right in so that your forhead almost hits the air canister to see it, but it's there.

Jon

 

here

 

Oh Carl, you man you!


TTTRx-7, you will probably be disappointed with the stock Nikki on a streetport.

 

Here's another pic that might be a little more clear. Just a little different angle is all. The idle adjust is circled in blue, near the center of the pic. Mixture, as you know, is circled in red.



Brian

 

That is a much better pic, it was just too cold outside to go take a pic one so I had to steal one from Yaw

 

It's a pic I've had for a while now. I took it a long time ago because people were often asking where to find these screws. So I've just kept it on my system for times like this.

Brian

 

The Factory Service manual sucks too. I paid $92 (including shipping) for a book that was reprinted using a 1972 copier!!!

Well, maybe not 1972 but all of the photographs are completely shot. The print is fine and the drawing/diagrams are good but anything that was originally a picture is completely useless.

And you are right, that damn screw is well hidden. Even with the FSM I had a hell of a time finding it.

 

Thanks so much for all of your help!!!!

I have 7 ASE certifications and it confused me so I can imagine back yard mechanics having problems too!!

You all are the greatest!!!

Thomas

 

Does anyone have a photo of the idle mixture screw on a California fb? The photos on these posts seem to have fallen off, and I'll be damned if I can find that idle adjustment screw anywhere. Also does anyone know if I'll have a hard time getting the California-only 'tamper-proof' cap off?

 

What year is the carb?

There's a cap on the screw that looks like a bullet, front & center of the throttle body, looking at the carb from the driver's side.

Stupid California "tamper-proof" crap.

 

You know I just figured it out last night. Carb is a 1985 off of a GS 12a. The idle mixture screw is the easy one to find, it's actually the idle speed that I couldn't find (and still can't find!). And someone must have disable the California tamper proof cap, cause there was a nice phillips cross on the head of the screw and i turned it no problem.

I was having trouble starting it in the cold (10 degF) at high altitude (I'm at 5000 feet right now), and so I figured I'd adjust the idle mix on the carb a little and see if that did anything. I know it has an altitude circuit in there somewhere, but it screwing with the idle really did help a lot, car started right up this morning (it was about 20 deg F).

 

Idle speed screw is all the way down below the linkage on the right hand side of the throttle body.