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Home > Tech Center > Carburetor FAQ
How can I lean down my carburetor to get better mileage?
First off, make sure the correct size, (cfm) carburetor is installed on the engine and be sure the idle mixture screws are properly adjusted (see page 6 of the Owner's Manual). You can always make your carburetor leaner, but this will not always improve gas mileage. Since every engine is different, there is no way of knowing how much of an affect leaning down the carburetor will have on your engine. You can refer to your carburetor owners manual and the calibration chart inside to lean down the carb. Start off light, but keep an eye on the plugs to make sure you aren't taking it too lean. You will see on the chart that you can lean the carburetor down in different percentages in different modes, cruise and power.

What metering rods and jets do I need to run with my combination?
There is no "pre-determined" combination of rods and jets for any given motor, accept for altitude corrective applications, which is 4% for every 3,000 ft of elevation. Every engine is going to require a different fuel curve. The best thing to do is run the carburetor on the engine right out of the box to build a baseline, then check the spark plugs and see how they look. You need to have a light brown, or tan color on the plugs. If they are too white or too black, you need to make adjustments, refer to the tuning chart in your carburetor owners manual. Plug reading gives you an accurate idea of what is actually taking place inside the combustion chamber. Please note, today's re-formulated fuels can leave a lack of accurate colorization. Purchase carburetor replacement parts online.

I am getting fuel in my oil, what is this caused by?
Fuel in the oil can be caused by several conditions including a ruptured fuel pump diaphragm, incorrect fuel line hook-up, and carburetor flooding. If the problem is carb flooding, check the following: Fuel pressure should not exceed 6.5 psi. Float level should be verified to be at 7/16. Refer to supplied carburetor owners manual. Verify needle & seats are free of any debris, and have a smooth range of operation and travel. Verify floats are free of any fluid by shaking the float, or submersing it in a safe, non flammable fluid.

My carburetor whistles, what causes this, how can I fix it?
This may be caused by a rip or tear in a base gasket, air horn gasket, or adapter gasket or some foreign material stuck in an air passage of the carburetor. Inspect the gaskets to make sure you have no vacuum leaks of any kind. Check to make sure carburetor is seated correctly, and is fastened with the correct hardware. You can perform a quick check to find external vacuum leaks (such as a leaky carb base gasket) by spraying starting fluid on suspected areas while the engine is idling. If the engine speed changes for a second or two after you spray an area of the carb, you're found the leak.

I can't get my idle below 1,000 RPM with my Edelbrock Carb?
Check for correct choke operation and adjustment. Make sure that the fast idle cam is not causing this. Verify the throttle arm rests on the idle speed screw. It is important to verify throttle linkage, and or throttle blades are not binding and have a free range of operation. Throttle return spring should be correctly located and adjusted. In most cases, the return spring should be positioned on the top of the throttle arm forward. This should have been confirmed when the Wide Open Throttle test was performed during the initial installation of the carburetor. Make sure all of the vacuum ports on the carburetor are being utilized or blocked off.

I purchased your 1406 carburetor and it is too lean, what should I do?
The 1406 is calibrated lean for fuel economy. In some applications, re-calibration of the carburetor may be necessary for optimum performance. See page 22-23 in the supplied carburetor owners manual. Step # 23 on the calibration reference chart is a good starting point for enriching the air/ fuel mixture.

Why can't I route my fuel line to the front of the Performer carb like a Q-Jet?
All of our Performer Series and AVS carburetors feature the PCV port on the front center of the carburetor; it can only be used for PCV. The fuel inlet is on the passenger side rear of the carburetor. Incorrect installation of the fuel line can cause severe engine damage.

How do I hook up my electric choke (voltage)?
The Electric choke on our Performer Series and AVS carburetors needs to be hooked to a "keyed" (while the key is in the on position) 12-volt power source, with a good ground. Verify there is no voltage when the key is in the off position. Do not connect the positive wire to the Ignition Coil, ballast resistor or Alternator.

My carburetor is flooding, what do I check?
Carburetor flooding can be cause by the following conditions. First, verify, with a fuel pressure gauge that the pressure does not exceed 6.5 psi. Floats should be set to the factory spec of 7/16, (see carburetor owners manual). Needles & Seats can be clogged with debris, not allowing them to close. They can be cleaned and checked when the float level is being verified. Floats can be sinking due to a leak. Verify floats are free of any fluid by shaking the float, or submersing it in a safe, non flammable fluid.

Can I run my PCV line to the rear of the carburetor?
We do not recommend routing the PCV line to the rear of the carburetor. We recommend that the PCV line go to the front, if you have power brakes, they go to the rear.

On the front of my Carburetor, which screw is air and which one is fuel?
Both Idle mixture screws on the front of our Performer Series and AVS carburetors control air/fuel mixture at idle. The left screw controls the left venturi and the right screw controls the right venturi. Refer to your carburetor owners manual to properly tune the idle mixture.

Which side of the carburetor do I put my dist vacuum line to?
Generally the distributor vacuum line goes to the timed (pass side of carburetor) port. This is mandatory on emission controlled applications.

My engine stalls when I come to a stop or a sharp turn, how do i fix this?
An incorrect float level can cause this to occur. Make sure that the float levels are set properly at 7/16" per the carburetor owners manual. Excessive fuel pressure can also contribute to this condition.

I see fuel dripping from the carburetor boosters at idle, what causes this?
Too much fuel pressure usually causes this and often times dirt in the float bowls can do the same. Make sure your fuel pressure does not exceed 6.0 psi, optimum pressure is 5.5 psi.