Question about Chevrolet Chevy

1 Answer

I need a diagram of a 4 barrel carb. i don;t know what a mixture screw adjust butterfly position and float level means.

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Chevrolet Master
  • 7,782 Answers

The mixture screws are at the bottom front of the 2 front barrels. They poke into the barrels from outside the carb.
Butterfly usually refers top the throttle plates that open and close the barrels, but if you have a quadrajet, they may also refer to the upper plates on the back 2 barrels that only open when the throttle is wide open.
The float level is the distance of the top of the float when the float valve is closed. As gas flows into the bowl thru the float valve, the float rises and eventually closes when the proper float level is reached by the gas.

Look here for example: http://www.holley.com/data/Products/Technical/199R8339.pdf

Posted on Sep 06, 2010

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

How to repair a flooding carburater


if the carburetor keeps flooding out, the float could be stuck in the up position. tap lightly on & around fuel reservoir to free. depending on age of carburetor, you might need to put in a carburetor kit.

Jan 23, 2015 | Cars & Trucks

1 Answer

How to adjust a carburetor


this sounds more like you need the carb rebuilt to clean out all the dirt in the small passages and replace the needle and seat as well as the float. the idle air mixture screw are at the front of the carb at the base one for each barrel the carb has. this year should have tamper proof plugs covering the mixture screws which the carb will have to come off to remove them.

Aug 28, 2014 | 1985 Chevrolet Chevy

1 Answer

Opel kaddet 1995 model. How do I adjust the


There are only two adjustments on a carburetor, the air mixture setting and the butterfly valve position setting. The air mixture screw is on the side close to the mounting flange, and has a spring behind the screw head to keep it in position.
To adjust it, look for the throttle valve screw which is also on the side, it ix the one that attaches close to where the throttle cable attaches to the carb. Turn the set screw down to let the car idle as slowly as possible. Now go to the air mixture screw. Turn it slowly first in one direction until the revs drop, then turn it out to the point where the revs are maximum. You might have to turn the screw back and forth until you find the best position. Now turn the throttle adjustment back to idle speed.

Aug 28, 2014 | Opel Kadett Cars & Trucks

1 Answer

I have a 1978 Chevy longbed with a 350 engine, dual tank. I have a new fuel sending unit, spark plugs, rebuilt carter quadrajet, new fuel pump, new spark plug wires, new distributor rotor. During...


The problem is in your carburator. Was it rebuilt in a shop or by yourself or a friend?Did they know what it was going on? It could be that the float level is too low. It could be that you have the plunger rod for the power valve in the wrong hole. It could be that you just need to adjust the mixture screws on the front. I would start with the mixture screws. Turn them in until they seat but don't force them,be gentle. Turn them out 1 and 1/4 turns each and start from there. You will have to turn each one separately from here.Set your curb idle about 500 RPM and turn 1 screw out until you hear the idle start to go up and then back it off until it starts to falter or miss, them come ahead just enough to bring the engine out of that. Then do the same with the other screw. Reset your idle and rev the engine by hand, a couple of cracks and then crack the 4 barrels open and let go. If it stalls then open the idle screws about 1/8 turn and try again. When the engine will return to idle off the 4 barrels without stalling your mixture screws are set right. Make sure you keep resetting the curb idle, usually 500RPM for a standard and 750 RPM for an automatic.
If you rebuilt the carb yourself then look on the rebuild sheet that came with the kit for your engine application and make sure you have the power rod in the right hole and that you have the correct float level. Different applications have different float levels even with the same size engine. Set them for the engine you have it on, if the carb came off something else. Hope this helps.

Mar 21, 2011 | Chevrolet Silverado Cars & Trucks

2 Answers

What is the float adjustment for a solex 44phn3 marine carb


I think you mean mixture adjustment.If thats the case its up tight and one and half turns back

Dec 24, 2010 | Volvo 240 Cars & Trucks

1 Answer

I HAVE AN 82 F-100 FORD PICK-UP WITH A STRIGHT 6 1B CARB. I PUT A NEW CARB BUT ITS SPILLING GAS AND THROWING BLACK SMOKE WHEN I START IT HOW CAN I ADJUST THE FLOT AND MIXTURES CAN YOU HELP ME THANK YOU...


You probably have a Carter carb. The metal tag on the top, held on by one of the screws should say YF/YFA. If so, you need to remove all the screws on the top and you will see the float. It should be .78 inches from the bottom(about 3/4 inch). I doubt being new that the float needs adjusted though. If it sat on the shelf long the float might be sticking. You will need to tap lightly (maybe using a wrench, or small hammer).
The idle mixture screw is in the front bottom of the carb but it has a limiter cap on it. It shouldn't really need adjusted either

May 11, 2010 | 1982 Ford F 150

1 Answer

Fuel mixture is too lean


many of the late model cars & trucks can't be
adjusted some of the carbs are preset some you can force and some don't have an adjusting screw for the jets if the carb is in good working order but needs a bit more fuel you u must adjust the float for more or less fuel check to make sure the float valve is clean free and not sticking ..

Mar 03, 2010 | 1987 Dodge D150

2 Answers

I need to adjust a carberater and get the 4 barrel to start working


Most likely you have a Holley carb. You may have a 460 engine. If you have the carb with a big vacuum pot in front of the carb, then you have a RPM governor. The RPM governor will work against the 4 barrel.

The main mixture for the idle jets can be adjusted like any old style carb. You may have plastic caps over the idle screws but take them off. Then use a vacuum gauge on any intake fitting and proceed to read the vacuum level as you turn the mixture screws. You want the mixture to reach a maximum RPM, then evenly turn the screw in until the RPM drops slighty and then balance for smoothest idle.

After this step adjust curb idle and see if this helps when the 4 barrel kicks in. Holley has different springs for the vacuum actuated secondaries and they are color coded. If the carb is original it should be right, but if the carb is of unknown origin you can check the proper vacuum spring, main jet, power valve and so on in a good Holley book. The mechanical secondaries are also listed with clearances to hand adjust.

By adjusting the mixture screws you have set the engine to idle just below peak vacuum pressure. This means you should have more vacuum to work the secondaries.

Feb 16, 2010 | 1983 Ford F 350

1 Answer

1967 barracuda carb backfires do I adjust screws in or out?


I would check the float level first if you are going to adjust the carb., carters like to flood and if you check your spark plugs you can tell if your running rich. The other adjustment you will make with a simple vacuum gauge.You should probally check distributor points,and timing as well. More info would help, like is it back firing up the carb or out the exhaust or when accelerrating or decelerating.

May 22, 2009 | 2006 Plymouth Scamp

1 Answer

I don't know where the air/fuel mixture screw is on my carb


There should be one screw (I'm assuming it's the Carter YF carburetor 1 barrel) that's by itself away from linkages etc, more to center at base of carb where it meets manifold, that is angled approx 45 degrees going in to base. That should be your mixture screw. What symptoms are you experiencing anyway?

Apr 03, 2009 | 1984 Ford F 150

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

244 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

75197 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22095 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

7782 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...