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carburetor tuning problem

 
joshcanfield
I love my Chevy Chevette!
Posts: 24
Joined: 02/13
Posted: 04/25/13 09:12 AM

I had my engine put in by a mechanic my friend suggested....bad idea i know... well I have found problem after problem from what this mechanic did...everything is half-assed and done cheapely and very poorly.

I am having problems working on my carb. I cant seem to find the tuning screws.

here is what I see...

Imag0377si

Imag0379e

so is this normal mixture keys? if so how do I get down in there to adjust them?  

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68scott385
I have an SS396 tatoo
Posts: 325
Joined: 07/09
Posted: 04/25/13 09:26 AM

Josh, your pictures are so large when compared to the veiwing window, it is hard to tell exactly what we're looking at.

The screw under or next to the throttle linkage is the idle SPEED screw.

The air bleed screws are at the front, in the throttle blade plate/section of the carb.

The way to set the air bleeds is to use a vacuum gauge attached to manifold vacuum port. Turn the air bleed screws, one at a time, in or out until the highest vacuum reading is obtained. THEN set the idle speed with the idle speed screw. You may have to go through the process two or three times to get air bleed and idle rpm optimized.  
68scott385 68scott385 68scott385

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joshcanfield
I love my Chevy Chevette!
Posts: 24
Joined: 02/13
Posted: 04/25/13 09:53 AM

ya sry about the image size the last time i posted in the forum people were saving them to their computer so they can resize it themselves. the problem I am having is getting to the screws to turn them. I can fit a needle nose in there is there a better way to adjust them in or out...also is this carb even worth fighting with or should I look into getting a different one  

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68scott385
I have an SS396 tatoo
Posts: 325
Joined: 07/09
Posted: 04/25/13 10:53 AM

Carbs are a personal preference...what one likes or learns to mess with.  
68scott385 68scott385 68scott385

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waynep712222
V-6 Camaros rule!
Posts: 122
Joined: 03/13
Posted: 04/25/13 03:12 PM

the second picture shows the idle mixture screws.....  those take a special DOUBLE D tool... easily found at parts stores...

the first picture shows a hex head with a slot screw kinda on the side of the carb.. thats the idle speed screw...

you will usually need a pair of tools...


OEM/Carburetor adjusting tool  Part Number: 25062
11-1/2 In. flexible shaft easily reaches into confined areas
Includes 5 quick change adapter tips for multiple applications
Convenient adapter tip storage located in handle and plastic boot
Sizes: double D, 1/4 In. hex, 3/32 In. hex, 2.5 mm hex, 4.5 mm hex
Part Number: 25062
Bits/Sockets Included: Double D, 1/4" hex, 3/32" hex, 2.5mm hex, 4.5mm hex


or


GP Sorensen/Adjustment tool Part Number: 779-5517


for carb adjustments ... you will also need a vacuum gauge... these read from 30 inches of vacuum to 15 pounds of pressure..



getting the carb idle mixture adjustment correct is like balancing on a ball..

you will need more info ..

i will put up some later ... but you might want to google this term    

idle mixture adjustment quadrajet

you will find several sites and pdf files on it..  

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Ravoll
V-6 Camaros rule!
Posts: 85
Joined: 02/12
Posted: 04/26/13 07:57 AM

I use a piece of 8 mm hollow aluminum tubing.It's been slightly pinched closed at one end so I can turn the "D" heads of the mixture screws.It's pretty redneck but it works,and was a lot cheaper than buying special tools that will only be used once.I also use the same thing to adjust my metering rod plunger.  
The older I get,the faster I was.

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