This valve controls the flow of gas to the carburetor while straining out contaminants.
The fuel filter or “strainer” on a carbureted Harley-Davidson Softail Classic is a component part of the fuel supply valve. This valve serves to control the flow of gas to the carburetor, while straining out unwanted contaminants from the fuel. The valve is vacuum operated for safety purposes, opening whenever the engine supplies sufficient vacuum pressure to actuate the internal valve. Care must be taken when performing this procedure to avoid damage to this valve. The length of time to complete this procedure will vary upon skill level, but will generally be approximately one hour.
1. Turn the valve handle to the OFF position. Remove the outlet and vacuum hoses from the fuel supply valve.
2. Attach a long piece of fuel hose to the outlet hose and place the other end into an empty gas can.
3. Turn the supply valve handle to the RESERVE position. Attach a hand-operated vacuum pump to the vacuum nipple on the fuel supply valve. Apply 1 to 10 inches of Mercury vacuum pressure to the valve to obtain a good drain flow of gas into the can. Allow all of the gas to drain from the Softail.
4. Turn the hex fitting, which attaches the supply valve to the Softail’s gas tank, with an open-ended wrench. Pull out the valve and filter assembly from the gas tank.