Jul 17, 2011 · When “ethanol” laced auto fuel is used, some neoprene needles swell up almost to the point of shutting off fuel flow to the carb’s float bowl. Stromberg’s OEM needle was made of a very high qrade neoprene and, generally, is unaffected by the use of ethanol. Another thing you want to do is to shut the fuel valve off at the tank when you shut down to preclude a hung float from filling the engine with fuel when the engine isn't running. ... This is the carb with the fuel solenoid. Mine leaks when I'm trying to start the engine. When I crank it leaks. ... MF 135 Carb Leaking Gas (1967? Continental Gas)Anyone help me on this one I have put carb kits in both my techmseth motors one on my old very old cub cadet tracktor and my old very old snowblower. They have the same carb put in the new needles and seats and cleaned everything very well.. if I don't shut the gas off at the tank after a few days seems like the carb leaks... any help there or just turn gas off.. thanks.. Leaking, worn valves in engines. ELECTRIC SYSTEM PROBLEMS: ... Remove the carburetor fuel bowl and see if any white deposits or grainy deterioted material is in the bottom. ... but once it gets hot, it will not restart after i shut it off to empty the bag. I usually have to wait 20 minutes or so before it will fire back up. Any help would be ...Use carb cleaner to clean the outside of the carb, on center stand with petcocks off. Then turn them on to see where the leak is on the cleaned carb body. If it doesn't leak, put it on the side stand and look for the leak. The no clamp fuel line could be cracked at the carb nipple. Re: Fuel Disappering FORD 641 Workmaster! I see 2 different problems. It sounds like you have a fuel leak on the carb - that could be extrnal - a gasket somewhere - or a float/needle valve issue internal.