Coupled with the everimproving technical advancements in modern outboard motors comes the dilemma of deciding whether to purchase a 2-stroke or 4-stroke engine to suit your particular needs.
Today’s outboards offer greater power, increased reliability, faster top speeds, more responsive handling and they are better for the environment than their predecessors. But, making the choice between a 2-stroke or 4-stroke outboard is not easy. Leisure Boating uncovered some of the pros and cons of both these motor types to settle the score once and for all.
WHAT THE MANUFACTURERS SAY
All outboard manufacturers profess that their particular range of outboard motors is better than the next manufacturer. While individual components and design elements might be better in one manufacturer’s outboards than that of other manufacturer, each will have positive attributes and elements attached to their particular brand. It’s human nature and good marketing to promote a brand of outboard motors by painting the rosiest picture.
So, don’t be completely swayed by how a manufacturer promotes its brand as this article aims to narrow the differences down between 2-stroke and 4-stroke engines. Only then should you start looking for a manufacturer that suits your outboard needs.
WHAT’S THE DIFFERENCE?
Outboard motors are generally categorised as 2-stroke or 4-stroke motors and this refers to the number of strokes the piston attains to complete a full power cycle.
Both these types of motors work on the same combustion principles yet they are manufactured and engineered quite differently, each with its own advantages and disadvantages.
In 2-stroke outboards, the fuel-air mixture enters the combustion chamber via a gap in the side of the cylinder and the exhaust gases exit through another exit vent in the cylinder. Initially, 2-stroke engines utilised carburetors to control the fuel-air mixture – but these days have been replaced by more efficient, computerised, direct injection motors.
Carbureted outboard motors are not particularly fuel efficient. The newer direct injection 2-stroke motors enjoy vastly improved consumptions and lower emissions. 2-stroke outboards are also often lighter than their 4-stroke counterparts as they don’t require camshafts, valves and belts.