Slow trolling is generally not harmful to big outboard motors. Outboard motors are designed to operate efficiently across a range of speeds, including low speeds for trolling. In fact, many modern outboard motors have specific trolling modes or features that allow them to run at low speeds for extended periods.
Outboard issues to watch out for when slow trolling
- Overheating: When an outboard motor operates at very low speeds, the water flow through the cooling system may be reduced. This can result in inadequate cooling and increased engine temperature. Overheating can cause damage to engine components, such as the cylinder head, gaskets, or piston rings.
- Carbon Deposits: Extended periods of slow trolling can lead to carbon deposits building up on internal engine parts. This is because the combustion process at low speeds may be incomplete, leaving behind residue. Over time, carbon deposits can affect the performance of the motor, leading to decreased power output, reduced fuel efficiency, and potential issues with the combustion process.
- Oil Dilution: Some outboard motors are two-stroke engines that require oil to be mixed with the fuel for lubrication. Trolling at very low speeds can result in an excess of unburned oil accumulating in the combustion chamber, potentially diluting the fuel mixture. This can affect the engine’s performance and may result in fouled spark plugs or other issues.
How to improve outboard performance when slow trolling
- Adequate Cooling: Running the motor at low speeds for extended periods can reduce the water flow through the cooling system, potentially leading to overheating. It’s important to monitor the engine temperature and ensure that the cooling system is functioning properly. If you notice the engine running hot, take steps to improve the cooling, such as increasing the speed periodically or adjusting the trim angle.
- Regular Maintenance: Regular maintenance is crucial for any outboard motor, regardless of how it’s used. This includes routine inspections, oil changes, lubrication, and checking for any signs of wear or damage. Following the manufacturer’s recommended maintenance schedule will help keep the motor in good condition.
- Fuel Quality: It’s important to use high-quality fuel and ensure that it is properly mixed with any required oil for two-stroke engines. Poor-quality fuel or incorrect mixing ratios can cause performance issues or damage to the engine.
- Avoid Extended Idling: While slow trolling is generally fine, excessive idling for long periods may lead to carbon buildup on internal engine components. If you plan on trolling for an extended period, it’s a good idea to periodically increase the engine speed for a short duration to clear out any carbon buildup.