The Development and Testing of Gasoline Engine Two-Stroke Oils for the European Market

The high power-to-weight ratio and low initial cost of the gasoline 2-stroke engine make it particularly suitable for use in mopeds (motorized pedal cycles), scooters, outboard engines, and some industrial applications. Problems associated with the use of oils in the various 2-stroke gasoline engines include exhaust system blocking, piston seizure, bearing corrosion, piston deposits and ring sticking, spark plug fouling, and combustion-chamber deposits. These are discussed with regard to their seriousness in different types of 2-stroke engines. In addition, seven bench test methods employed in Europe for evaluating 2-stroke mixtures are described. Since it is considered that road tests are a necessary part of any program to develop lubricants for 2-stroke engines, details are also given for road and/or service test procedures.