Autolite 1100 Carburetor

Autolite 1100 carburetor parts.All technical information including videos assume parts used are our brand. Parts from other sources may not install, or function the same way.
About the Autolite 1100 Carburetor

  • The Autolite 1100 one-barrel carburetor was included on 170″ & 200″, 1963-69.
  • 1963-1967 (some) came with a spark control valve.
  • 1968 – The venturi size was changed to 1.10 and there was no control valve.
    The distributor was changed to use a mechanical advance     instead of using the venturi vacuum previously.
  • 1967-1969
    – Two diaphragms were used. The added     diaphragm is used as an anti stall dashpot. Only one diaphragm was used prior to 1967
  • Correct venturi size for Mustangs was 1.10″, or 1.20″
  • When no tag is present, Identification can be done by inspecting the base. You can sometimes find a Ford part number there.

Buy your Autolite 1100 carburetor kit here.

Free Autolite 1100 manuals
1968-69 Autolite 1100

Power Valve

At higher speeds, the engine vacuum drops which causes the power valve to open and allow more fuel to flow.
Autolite 1100 Choke

Do not remove the power valve assembly when rebuilding, but it does need to be free to easily move up and down. For sticky power valves spray liberally with silicon spray lubricant and work it up and down until it is free. Worst case is you will have to remove the clean out plug on the top of the carburetor so that you can get at the cylinder for cleaning. You will need a new clean out plug, or patch up the old plug with JB weld (don’t get any inside). A surge at high speeds (steady throttle) might indicate a power valve
problem. Change the power valve timing to open sooner (at less throttle opening) by adding additional calibrating shims, on power valve rod (see illustration above). If less than 4 shims found on rod, add 4 shims; if more than 4 shims found on rod, add fewer number. Total number of shims on rod must not exceed 8. These shims are not produced and you only want to take the power valve apart as a last resort.

Autolite 1100 Main Jet

This is where the Autolite 1100 main jet resides. Due to the difference in gasoline, the jet size that was originally installed on the 1100 isn’t that relevant anymore. Be sure you are using the correct jet size, otherwise you chance ruining your engine. Test your main jet
by running your vehicle for 20 minutes at a sustained speed. Pull a spark plug and look at the color. Gray is perfect. White means you are too lean and need to move up one size.
Black is too much fuel and you need to move down one size. Do this one size at a time until you get a good gray colored plug. This test is only valid when your engine and electrical system are good condition.
Autolite 1100 Jet

1966 Rough Idle & Poor Fuel Economy Correction.

This condition may be caused by the fuel bowl vent valve being out of adjustment. Check and adjust the vent valve each time the carburetor idle speed adjustment is made. 

Buy your Autolite 1100 Main Jets.

Did you lose your check weight?

Autolite 1100

These are no longer available, but you can make your own. Use a 3/16″ aluminum rod, cut 9/16″ long. File the end a bit as pictured. Weight will end up being about 1 gram.

Watcha video about On The Bench Adjustments

Watch a video about rebuilding the Autolite 1100 carburetor. Part 1 – Teardown

Question
I seem to have a problem with my carb that I rebuilt recently. It is a C8PF-D on my 1963,170 cu in Falcon with auto trans. Its a manual choke and has the spark control system and a diaphram on each side. We adjusted the mixture screw till it ran nice and took it for a small drive. Upon returning it would not idle hardly and was running very rough. We adjusted the mixture screw again and it started runnning properly agian. The next drive we took it ran great, but when we arrived home the same rough running and no idle was present agian. It acually died on us instead of idling. My question is if the mixture
screw is backing itself off due to vibrations etc.? Could the screw or spring be worn out or could it be the carb hole and threads worn out? I hope you have run across this before and can point me in the right direction. I thought about loctite to hold it, or maybe a new
spring and screw.

Answer
1st off don’t use anything on the threads. That would probably ruin the carburetor. It does seem the screws are moving from vibration. I would replace the idle mixture screw and spring.

Watch a video about the Autolite 1100 Flooding Troubleshooting

 

I am having an issue with my autolite 1100 stumbling when under way. Everything is fine at rest. I notice if I sit on the fender and rock the car the engine begins to stumble. When I set the float level I used the Fuel system service instruction worksheet provided in your rebuild kit and it stated to set the float level to 1 – 3/32 for my 65 Mustang 200 A/T, which I did. Do you think its possible I would need to set the float level higher or do I possibly have something else going on? Fuel pump filter and strainer are all 2 months old. As is the carb rebuild.

The 1st thing that comes to mind is that the flow bowl is warped. Check my video about fixing the 1904 with heat. Same idea.

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Carburetor Percolation

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Percolation can happen when your engine gets hot, then you turn the engine off and the fuel boils over, sometimes over the top of the carburetor, or more often, simply evaporates. Back in the day we called this vapor lock, which simply meant that the fuel turned to vapor before getting to the engine.

This has been a more common problem these days because our gas has a lower boiling point than it used to. Yup you guessed it, ethanol.

This makes it hard to start the next time. You have to crank and crank, or pour a bit of gas down the carburetor to get the engine started.
What can you do:
  • One of the best ways, but a lot of work, is to run a 3rd line from the fuel pump back to the gas tank. This extra line will help cool the fuel, allowing the fuel pump to pump gas instead of vapor. There are some fuel filters out there that include a return port. There are also return regulators available.
  • Put heat wrap around the fuel line in the engine compartment.
  • Put a spacer under the carburetor mount. These are hard to find so you will probably have to make one. Yup, a mill would be handy about now. And you will probably need to put longer studs in the manifold to accommodate the extra height.
  • Instead of a spacer add extra mounting gaskets. A couple of 1/32 thick gaskets isn’t going to do much. Hopefully thicker gaskets will be available for your engine.
  • Add a helper electric fuel pump. Just before startup, you run the electric pump for a few seconds, then turn it off. Use only a low pressure pump. 7 lbs max. You may end up also adding a regulator because you don’t want the pump to overrun your mechanical pump. Most 1 & 2 bbl carburetor run 4-4.5 lbs. Bigger carburetors might handle 5-6 lbs.
  • Cool the engine with a cooler thermostat, bigger fan, or bigger radiator.
  • Try different brands of gas. Different octanes won’t help you here.
  • Use non ethanol gas if you can find it.
  • Remember when we used to put wooden clothes pins on the fuel line? The clothes pins act like a heat sync, drawing heat away from the fuel line and my wife says the wooden clothes pins are still available at the dollar store.
Anyhow, the basic answer here is to cool your engine and/or fuel.




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