The purpose of this test method is to evaluate lubricating oils used in two-stroke gasoline engines with regard to piston ring sticking tendencies and engine internal cleanliness at high temperatures. In this test, the tests of reference oil and candidate oils must be performed on the same day to compare their relative performance.

The test conditions of high speed and maximum load over a period of three hours were selected, after consultation with the engine manufacturer, to simulate extreme field service.

The test utilizes a Honda AF27 motor scooter engine with a displacement of 49 cm3.

This method is appropriate to assess and develop the detergency performance of two-stroke gasoline engine lubricants.