If you own a boat which features an outboard engine, it is essential that you pay attention to any signs of excessive vibration. Vibration can be caused by a number of problems, all of which require immediate repair work. So if you sense that your engine is rattling around too much, you should not ignore the problem. Return to port as soon as you can and have the engine and boat inspected by a qualified repair specialist. Below is a guide to 2 of the main reasons that outboard engines start to create excessive amounts of vibration.
Loose engine mounts
Outboard engines are not built into the hull of your boat as the engine of a larger craft would be. Instead, the engine on your vessel is attached using an engine mounting. The engine mounting is bolted to the hull of the boat and forms a kind of cradle in which the outboard motor sits. The mounting is fitted with flexible rubber strips which help to absorb the vibrations created when the engine is running. However, when exposed to water for an extended period of time, the attachments which connect the mount to the hull and the shock absorbing strips can begin to fail. When a failure of these two components occurs, it can lead to excessive vibration which seems to travel through the hull of your boat. As well as being very unpleasant for everyone on board, if left unattended, this vibration could cause severe damage to the integrity of the hull. If your outboard engine is vibrating, you should inspect the condition of the engine mount. If you find any signs of damage, you should take the boat and mount to a boat mechanic who will be able to advise you if you need to repair or replace the component.
Damaged propeller blades
The propeller which is attached to the engine of your boat spins around at high speed to generate the thrust required to push your craft through the water. The spinning creates large centrifugal forces. Propellers are finely engineered and balanced so that this energy is dissipated into the surrounding water. However, if one of the propellers on your vessel is damaged, the additional drag it creates as it passes through the water can cause it to become unbalanced. When you get back to base, you should carry out a visual inspection of the propeller. If a blade is misshapen, you should replace it with a new blade.
For further advice, you should contact a diesel marine engine repair company.