1990 Johnson Evinrude "ES" 9.9 thru 30 Service Manual, P/N 507871, Page 27Get this manual
FuelOil Ratios Lubricant Only the following lubricants should be used:
Evinrude Outboard Lubricant Evinrude XP Outboard Lubricant Johnson Outboard Lubricant Johnson GT Outboard Lubricant OMC Cycle Motor Oil
They are formulated to give best engine performance with least combustion chamber deposits, least piston varnish, maximum spark plug life, maximum corrosion protection and best lubricationIf Evinrude or Johnson Outboard Lubricant or OMC 2-Cyce Motor Oil is not available, another NMMA certified TC-WII oil may be usedLook for the certification information on the container labelRunning or storing an engine on leaner than recommended fueloil mixture may result in powerhead damage
INote Avoid the use of the following as life: could damage your they engine and or shorten spark plug