Carburetor

[1930AADUMP]

Without any winter storage for my AA, I plan to run and drive it as weather allows. Most likely once per week and perhaps less at times. Do you guys ever run the carburetor dry after each use under those circumstances? I used to do so for my '41 John Deere I sold for the AA. Thank you.

Paul

[KimVanOrder]

I see no need to. Think about it. The gas in the carb. is no more likely to go bad or do any damage than the gas that is in your tank, or in your family car. If you were going to leave it for the entire season. Well, I still wouldn't. I leave the gas in all my small engines year around and never have any trouble with them. What I think usually gets people in trouble is using dirty gas cans that transfer dirt into the carb. systems.

[birdacre]

i run my carb dry each time in the winter. i have had the engine turn over and over, fuel pour out carb and plugs taken out and bone dry. i suspected some icing in carb from condensation. i do not have this problem anymore when i run it dry. hope this helps.

[robie]

Been researching "AA's" for a year or a bit more, and it seems the majority have no breather,ie. the down turned air filter seen on most "A's" and some "AA's". is there a reason? here in southcentral VA. thats an open invitation for a mudabber or mouse to move in...neither are good

[ModelAkid]

If your Model A-AA will be sitting for a while in a cold damp climate draining the entire fuel system is a good idea as water condensate can form in any petroleum product like gas, diesel or engine oil. The easiest and most thorough way is to drain the tank using the drain on the bottom of the cast iron sediment/condensate filter on the firewall (on the carb if you have a late '31), then the drain plug on the bottom of the carb. In addition to the fuel this will pretty much drain out anything else that shouldn't be in there.

[Chris Haynes]

On the other hand gasoline is oil. Oil prevents rust. Top off the gas tank and add Sta-Bil.

[ModelAkid]

Petroleum products do not stop rust when the oil & water are separate. Water will sink to the bottom of gas, diesel & engine oil and remain separated and rust the bottom of whatever it is in, a fuel tank or a crankcase. Sometimes if the cast iron or the glass firewall filter does not have the condensate water drained out it can freeze and break either type filter. Alcohol in gas is what used to be sold separately as the fuel additive called "gas line antifreeze". The alcohol combines with water and mixes it with the fuel so it cannot freeze or rust and the engine combustion turns it to water vapor out the tailpipe.

[ModelAkid]

Chris's advice will work also and not only prevent condensation but also keep the gas from going bad if you don't want to empty the tank. Sta-bil does not prevent condensation but topping the tank does that by filling the air space in the tank which is where the condensate from the damp air comes from.

[1930AADUMP]

The truck will not sit idle all winter. I plan to run it as often as weather and time allow. I have been using a product called Ethanol Shield in all my gasoline engines without issues to date. I know there are a lot of products on the market designed to mitigate some of the complexities of modern gasoline.

My unfamiliarity with the truck, engine and carburetor gave me pause and thus the reason for my carburetor question. A clean tank (unsure of that but no problems noted thus far), a filter of some sort (do not have one yet) and it appears to matter little whether to run the carburetor dry after intermittent use.

Perhaps a personal decision based on the various experiences and condition of ones truck.

Thank you for your responses.

Paul

[ModelAkid]

Paul, Henry built your truck with 2 filters and a water trap. No need to add more filters unless you have rust particles in your fuel tank. Then you might add the little screen that the dealers sell which goes on top of the outlet pipe in the tank. The first filter and water trap are on the firewall (side of carb if late '31). The second filter is in the carburetor. A modern filter installed in the fuel line will only cause problems on the gravity fed, unpressurized Model A/AA fuel system.
No need to worry about alcohol in Model A fuel. They were made to run on much worse fuel than any gas you can buy today.
Just as an experiment I'm going to get some E-85 (85% alcohol fuel) and see how my Model A runs on that. If anyone on the forum has already tried that, let me know.

[1930AADUMP]

Thank you ModelAkid. I do not know the history of the truck but it was a work/farm truck survivor for sure. I have put about 25 miles on a rebuilt engine thus far with no issues. There is sediment in the fuel bowl (large pieces at the bottom) that I have yet to clean out. I plan to drain it and clean it as I should have done prior to engine rebuild. My guess is the gas tank while not "clean" is not in bad shape either. There are fuel bowl filters I thought about adding to perhaps trap the smaller particles that may enter the fuel line and into the carburetor. Anyone keep a spare carburetor in your truck?

It otherwise starts, runs and drives just fine in 50 degrees as well as 20 degrees.

Paul

[ModelAkid]

Paul, the filters Henry provided will keep the carb clean as well as can be expected but if there are some rust pieces in the fuel tank they will clog up the tank outlet pipe so nothing will come down the pipe. (I've had that happen many times). Clean the tank as well as you can and then put the little screen the dealers sell on the tank outlet so the pipe won't get clogged. If the problem is severe the screen in the tank will eventually clog. Then you might have to consider some of the tank sealer the dealers sell.
When you clean out the firewall filter you might also want to remove the plug on the bottom of the carburetor bowl (not the bolt that holds the carb together, unless you want to take the carb apart). If it has not been cleaned out in a long time there could be "stuff" in the bottom of the float bowl. While you are at it, after the fuel line & carb are drained, might as well check the screen in the carb too. It is accessed by removing the brass plug on the carb bowl that faces forward.