1943 Case SC carb problems.

Hey guys. So I got a new problem. This morning when I tried to start my Case SC with a Zenith carb, gas just started running right out onto the ground. Choking it just made matters worse. When I would choke it, then push the choke back in, even more gas would rush out. Could not get it to start. I have to have to starting before Tuesday because that's when I get new tires. Messed up float?

That would be right in my book. Either it is just stuck or it has developed a hole in it. You could possibly free it up if it is stuck by gently tapping the side of the carb. That doesn't always work but the alternative is to take it apart and check it out.

Float probably is sticking. Wack the side of the carb with the handle of a screwdriver sharply while it is running & see if that helps. If not, you'll probably have to take it apart and clean it.

Sometimes a piece of trash gets caught in the needle valve.

The first thing to try, close the fuel valve, open the separator bowl, clean it out, be sure the screen is in place, clean it also. If there is a collection or rust or dirt on the screen and in the bowl, the tank may need to be removed and cleaned.

Next get a clean glass ready. Remove the drain plug from the carb bowl and catch the contents. Again look for contamination.

With the plug still removed, open the fuel valve and let some gas flow through the open needle valve. You can LIGHTLY tap on the carb with a plastic screw driver handle while it is flushing.

Replace the plug, see if the flooding stops. If so, it was probably trash. If it continues the float may be sunk or the needle valve is worn, loose, or damaged.

If it persists, remove the carb, take it apart and see what's happening. Don't be afraid of it, they are simple and field serviceable. Just work over a clear surface so anything dropped doesn't get lost. Many times they can be eased apart without needing gaskets. Give the float the shake test, feel for gas inside one of the pontoons. Check the condition of the needle valve, be sure the seat is tight against the gasket, check the float level.

A simple test before putting it back together, turn the top upside down, suck on the fuel fitting, put your tongue over the hole. If it holds vacuum, it's good. No vacuum and it will still flood. Cleanliness is essential. If the tank is contaminated it will continue to trash the needle valve. Inline filters are not a good idea on gravity systems. Before reconnecting the fuel line, turn on the fuel, let the line flush out anything that might be on it's way down or that may have entered the line while it was disconnected. I like to let it slow trickle while making the connection.

Lots of how to information and specs online and on Youtube.

If your carb is original, and nothing broken, save it! Better quality than the aftermarket fit all's.

Do what Steve mentioned, shut the gas off and clean the sediment bowl and screen and drain the carb. Now, what I am going to suggest takes some finesse; with the carb drained and the drain plug closed and the fuel shut off try to start the engine with he throttle wide open and no choke. There usually is enough gas left in the manifold and flooded engine to run the engine for a few seconds. If it does start and run for a few seconds and then die turn the gas back on for about ten seconds to refill the carb. Now, shut the gas back off and try to start it. The engine should start and run on the gas in the carb for fifteen seconds or so but while it is running turn the gas back on slowly and see what happens. If the engine chugs and smokes the carb is still running over and needs to be taken apart, if the engine runs OK you might be good to go but I use the word might literally. Sometimes the vibrations from the running engine loosens up the float and gets it working again. If you have a hole in the float or junk lodged in the fuel needle valve all bets are off.