Two Strokes vs. Four Strokes

The Environment Protection Agency (EPA), has said that each outboard motor manufacturer must decrease overall emissions of its entire line by a certain percentage by the year 2006; this does not mean that all motors in a line must be replaced. Some manufacturers will have a combination of four strokes and two strokes, depending on what is best for each horsepower. How manufacturers decrease their engine line's emission is up to them. New four stroke motors are designed to meet emission-reduction EPA requirements for 2006. However, engine owners are in no way responsible for making changes to existing engines to meet these requirements. Therefore, if you already had a two stroke engine before 2006, you will be able to use that engine for as long as you like.
Cost factors: In general, four stroke motors cost slightly more upfront to purchase than two stroke engines. Four stroke motors are far more fuel-efficient than two stroke engines, so fuel costs are lower. The savings in fuel expenses will compensate for the higher initial cost of a four stroke engines. For basic maintenance, four stroke engines use fewer spark plugs than two strokes but need periodic checking of crankcase oil level and regular oil and filter changes. Both four and two stroke motors require winterization and periodic maintenance.

Four stroke performance: Four stroke engine exhaust is cleaner and basically smok

eless because, unlike two stroke engines, no oil is mixed with gas. Two stroke engines generally weigh less than four stroke engines of comparable horsepower. Four stroke engines are quieter and smoother-running. Power is not an issue because horsepower ratings are standard regardless of the technology.
Two stroke or Four stroke: More and more boaters are asking this question, and there is no simple answer. You will need to evaluate your circumstances, requirements, and priorities. The information included here should give you a better understanding of the advantages of both four and two stroke engines and help you make your decision based on the facts. Whichever you buy, you'll be able to continue to use it for as long as it lasts.