Several basic items should be checked. First, is the fuel tank full of fuel and vent open? Water in fuel or excessive amounts in water separator? Your engine should idle between 1250 and 1450 for stock motors and 1000 to 1200 for Mikuni aftermarket engines.

Is the fuel line pinched from a heavy object sitting on the line, or is a tight connection restricting flow? Are there cracks in the line or connections, allowing air to leak into the fuel system? If you placed your fuel tank near the front of the boat, did you use a recommended 5/16” or 3/8” fuel line? If you added a quick disconnect to the fuel tank, especially OMC type, you may be restricting fuel.

Do you have rope, weeds or wire wrapped around your propeller? Is your fuel filter dirty or plugged? Is your engine oil low?

Tip: If you use an in-line primer bulb, do not over pump the Mikuni carburetor aftermarket engines. These carburetors have very small needle and seat valves and if you over-pump the bulb, you can push small particles of debris past the fuel filter element and into the needle and seat where it will plug the carburetor. This can stop the engine or restrict fuel during acceleration or at full throttle.

Also, the Mikuni carburetors have a low speed idle jet on the side of the carburetor. (brass screw). If your motor experiences hesitation at throttle-up, turn the screw in. The idle screw is normally set at 1 and a half turns out, but it can be run as far as all the way in. Each engine and carburetor are slightly different.

If you are in a state that is using 10% ethanol and you aren’t using our fuel tank and new fuel lines, the ethanol can deteriorate the older system and cause particles to enter the fuel system, plug up fuel filter, etc.