Small engine fuel system

[stuffbuilder]

So I got a small engine for a motorboard project I'm working on. Its one of those 2-strokes with two fuel line hookups on the carburetor, one main fuel hookup and one return hookup for the primer. The engine didn't come with a gas tank, and all the tanks I can find with two fuel lines are either too small or too odd-shaped. I want to use the tank for a larger, 4-stroke engine, but they only have one hookup. If I were to mount the tank above the carburetor so gravity feeds the fuel, do you think I could just plug up the return hookup and not have to worry about priming it to start? I'd like to get somebody else's opinion before I drop $40 on a tank.

[Crna Legija]

just try with a old soda bottle

[jrrdw]

As long as you don't push the primer bulb and blow the plug out and it has a choke it will work. Make sure the gas cap has a vent hole in it.

The only issues I can think of are 1. a good mount for the tank and 2. reducing the hose size and no leaks there. You may be able to find the/a brass hose barb that will reduce the fuel line.

[stuffbuilder]

I'm guessing I should probably also put a shutoff valve on the line to keep the engine from flooding when its not running. It does have an electric starter so its not like I'll have to yank a pull cord a bunch of times go get the gas flowing.

[Technician1002]

Without the primer bulb, it may be very hard to start. That type of carb was designed to operate in any position, including upside down. Because of the design, they don't gravity feed very well. Use a small hypodermic syringe on a tube to "Prime" the carb and use an aquarium air valve to seal off the line after priming so it doesn't leak and you don't have to leave the primer attached. That carb style is often used on hedge trimmers, chain saws, weed eaters, etc that may be laid down at any angle.