of the lubricant was determined using the jaso standards and an iso detergency standard that are currently used on commercially available two stroke motorcycle lubricants there are four levels of performance jaso fa fb fc and iso egd jaso fa is the lowest standard and iso egd is the highest standard the performance criteria that determine the quality of a two stroke motorcycle lubricant are set out in the jaso engine test sequences details of which are available from the japanese automotive standards organisation a short summary on each test is given below the tests determine the two stroke motorcycle lubricant 39 s performance in comparison to a reference two stroke motorcycle lubricant of known quality and they give the result as an index number the parameters that are measured are this test determines the two stroke motorcycle lubricant 39 s potential for the breakdown products on combustion to build up to such a degree that they affect the engines performance possibly causing failure more likely reducing top speed and increasing fuel consumption this is referred to as blocking index bix the minimum index result for jaso fc standard is 90 and the minimum index result for jaso fb standard is 45 this test determines the high temperature detergency of the two stroke motorcycle lubricant the two stroke motorcycle lubricant 39 s ability to control deposits on.