Power boats driven by modern motors are way more efficient and reliable than their predecessors but with the leaps in technological advancement comes problems that are often more difficult to pinpoint. Even though boat owners have greater technical ability these days, there are still faults that occur with regularity and disable the motor. Let’s find out what these faults most commonly are.
Boat fuel gauges are often not very accurate and this makes running out of fuel that much easier, and it’s on the rise. Running out of fuel at sea is dangerous as it leaves the boat and its occupants at the mercy of the sea until help arrives or until the spare fuel carried aboard has be utilised and bled through the system. It is very easy to miscalculate the fuel usage of a boat if the conditions change to a strong headwind, as an example. Some fuel additive treatments leave sediment behind which can clog the fuel filter, so using a treatment that leaves residual deposits of combustible as its byproduct is preferred.
A large percentage of engine failures are due to faulty electrics. Check the obvious first such as blown fuses, loose wires and badly connected battery terminals.
Overheating is mostly caused by blockages in the intakes. Plastic bags are often the culprits causing the blockages which then result in overheating. Failed impellers are also one of the major causes of overheating. Often the broken pieces of the impeller blades make their way into the cooling system and need to be removed before the new impeller is fitted.
BATTERIES & ISOLATORS
A battery isolator switch failure can bring your boat to a halt, particularly if the switches are exposed to sea moisture and spray. Carry battery isolator spares with you to circumvent total engine failure. Other battery related problems are a drop in the batter fluid level causing the battery to lose its charge and faulty or loose terminals. It is advisable to have a charged power pack on hand on the boat to be able to restart the motor when needed.
FOULED DRIVES & PROPELLERS
Many breakdowns can be attributed to fouled propellers. Whether it’s tangled fishing nets, rope or other materials, these can cause major problems and cut your trip short, if not halt it in its tracks. With outboard motors it is usually possible to get the offending material off the propeller, but with outdrive and less accessible propellers, the removal of the material can be very difficult. Hopefully the shaft has not been bent in the process or the propeller damaged.
COMPLETE MECHANICAL FAILURE
Complete engine failure seldom occurs with broken cams, cracked cylinder heads and dropped valves. These types of incidents are few and far between and usually occur due to extreme neglect and lack of maintenance.
Drive belts can be the cause of engine failure. It is not always obvious when the engine is at idle, that the belt, or belts in some cases are slipping. But as soon as the engine comes under load, the belt starts to slip. A black residual dust around pulleys is often an indicator that the belt is slipping. Keep spare belts on board and regularly test the tension of the belts to ensure they are at the correct tension.
HOSES & CLAMPS
Hoses can perish due to the constant vibration on the boat and hose clamps can work themselves loose or become corroded. Do a visual check of the hoses and clamps and carry spares with you in the event of an emergency.