08/17/2026
One of the worst things for a boat motor is to sit unused. While this is true for any engine, boats are especially prone to sitting idle for long periods. When left unused, the combination of stagnant fluids, ambient moisture, and modern fuel chemistry causes rapid mechanical degradation.
Another major issue that leads to breakdowns if left unchecked involves the low-pressure fuel pump. When the diaphragm inside the pump is left dry for too long, it slowly stretches and loses pumping power. This starves the motor of fuel and, in some cases, can cause the diaphragm to rupture completely, leading to fuel dilution and catastrophic internal failure.
On a fuel-injected motor, a failing low-pressure pump starves the high-pressure pump, resulting in expensive repairs. If it’s a carbureted motor, you will notice a lack of power and a rough idle, which is exactly how this customer's motor was acting.
The customer sent a video of the engine behaving erratically at idle. One of the telltale signs of a low-pressure pump failure is a "lean pop" (a sharp popping or backfiring sound that happens when an engine does not get enough fuel). This means the air-fuel mixture has too much air and too little gasoline, causing the fuel to burn too slowly or explode out of turn.
This is a very serious issue that can lead to scorched or melted pistons, seized cylinders, detonation, engine knocking, burnt valves, or a blown head gasket.
If you think you might be experiencing fuel delivery issues, don’t ignore them. Reach out today before it's too late!
