2 stroke engines weigh less than 4 stroke engines. However, 4 stroke engines don't dump oil into the water like 2 strokes do. If you want to enjoy the ocean we have and want it to get healthier, stay away from 2 stroke engines.
Well, the Evinrude ETec and Mercury Optimax are two and three star rated engines, they do not pollute any more than do the four strokes, the total environmental impact is the same, net for a year of useage. They are also extremely fuel efficient, more so than many four strokes and the ETecs are very quiet as are the Gen II Optis.
Thing is we are talking about a small--SMALL--inflatbale that will be required to be portable according to the OP by two to four people. A four stroke 25 horse is 50 percent heavier than the two stroke Yamaha or older Merc 25.
The environmental sensitivity I applaud, let's begin with no more spear fishing, no more energy consumption, no more air conditioning, scrap your car to the landfill (don't sell it), don't purchase Chinese products, don't buy groceries in plastic, don't buy any over packaged products (DVDs, CDs etc) and certainly no more dive gear which is replete with environmental stinkiosity being made from petrochemical plastics, composites and all sorts of bad chemicals that kill pretty little fishes and furry animals.
Environmentalism is a good thing but let's direct our efforts where it matters and counts where there is real impact rather than outlawing sunscreen and fiussing over a miniscule amount of oil from a tiny little 25 horse outboard. Like building restictions on condos, automobile guzzler taxes, mass consumption of portable fuels to make electricty and fertilzer runoff and beef production which itself has a huge negative enviromental impact. Yep, them burgers your woofing down have more impact that the guy with the 25 horse two stroke. When you spear a fish, push that 100 years into the future, you just killed generations of fish and limited the gene pool. That fish might have been the one with a benificial gene that could have made a difference for the species health. Don't bore me with false feel good and do nothing environmentalism.:no
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