Model Engine Company of America


The main cause your marine engine dying when you place it in the water is usually because you tried to tune your engine out of the water.

Read this "How do I set my needle valves on marine engines? How many turns out should my needles be set at?"

Other causes are the tank arrangement. As the boat it propelled forward the pick up in the tank may be starved for fuel. All the fuel goes the the rear or stern of the boat from not only the forward force but also the the bow lifting up.

Shopping without emptying the tank is usually caused from a pin hole in the fuel line inside the tank.

The tear resistance of silicon tubing is very low and it's not uncommon to develop a hole where the fuel line is assembled over the edges of brass tubing. If the engine runs well on the first half of tank and then quits, it's almost always caused by a hole in the pick up line inside the tank.

When the fuel level is higher than the hole in the pick up tube in the tank the engine will draw fuel through the pick up tube and the pin hole.

When the fuel level drops below the pin hole the engine will start to draw air. This results in the fuel mixture leaning out and the engine dying.

A tell tale sign of this are bubbles in the fuel line while the engine is running with a low level of fuel in the tank.


See also cause of erratic running

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