- According to the EPA, two-stroke engines - which power a variety of other watercraft as well - are a leading source of toxic water pollution.
- Mowers powered by two-stroke engines, for which gasoline and oil are mixed prior to ignition, are dirtiest.
- See also the articles on Hemi engines, rotary engines and two-stroke engines.
- Myriads of old cars, beat-up buses and superannuated trucks asphyxiate urban areas with their deadly exhaust, while the dirty two-stroke engines that power small vehicles emit ten times as much fine particulate matter as modern cars.
- However, instead of a large battery to power an electric motor, you have a fuel tank and a small piston engine, usually two-stroke, complete with air-filter, carburettor and exhaust pipe.