Inboard engine maintenance

Understanding the difference between the modern road vehicle experience, i.e. never lifting the bonnet; just climbing in, simply turning the key and setting off - and the very different experience for boats is crucial for enjoying petrol-engined boats safely.

Owners of petrol engined boats have to take a disciplined and well-structured planned approach to boat care, trip preparation, fuelling, and the after use regime to reduce risks.

Staying safe means having appropriately constructed and well maintained petrol systems. It also means never dropping your guard and keeping alert to any signs of a petrol leak in the fuel system before it develops into something threatening.

With petrol engines often located in difficult to ventilate spaces and close to spark generating equipment, it is not difficult to understand that flammable petrol vapours could ignite easily. Such combustion is both rapid and powerful and in the wrong circumstances, the skipper, crew and possibly bystanders can be in danger.

  • Caravan LPG refrigerators on boats with petrol engines have caused numerous explosions when the low-level permanent flame of the fridge burner ignited stray vapours. So don’t risk using one!  Choose electric refrigeration which is suitable for marine use.
  • Plan ahead and well before the season starts. Set aside time for a thorough inspection of the whole petrol supply system from filling point to engine. By sight, touch and smell, check for signs of damage, deterioration, looseness, cracks, weeping and leaks.
  • Older petrol engines usually require higher levels of caution and care, for example checking any side-draught carburettors drip trays are empty and that flame trap gauzes in place are in good condition. Check the flame trap is also in place on any fuel tank vent outlet.
  • Similarly watchfulness is needed on high wear items on older engines such as carburettors and fuel pumps where any early signs of issues could indicate replacement or reconditioning is a safety critical action.
  • All inboard engines should be fully serviced and checked routinely by a competent marine fitter including the engine, fuelsystem components and controls.
  • Always use marine grade, or manufacturer-supported parts when replacements are needed.

Next: Safety before you start »