as far as jet skis are concerned, 4 stroke technology is not nearly as good as it needs to be yet for me to drop in a four stroke rather than a two stroke. in the dirtbike world, for motorcross id go with a two stroke anyday, lighter, far better response and power to weight ratio, typically a higher static compression ratio, its sad though, two strokes pollute too much cause the oil they burn, lets not say 4 strokes are environmentally friendly either. Its all the EPAs fault that kawasaki stopped making the 2 stroke SXR, they gave kawasaki alot of crap for all the pollution it causes. same with yamaha, they dont make alot of superjets any more.