Home › Forum › Ask A Member › 63/64 Evinrude Fuel mix › Re: 63/64 Evinrude Fuel mix
OMC, in my impression, really did not do a good job of handling the fuel mix question and associated environmental controversies. Sometimes changed guidance is associated with changes in the motors, and sometimes is just a changed corporate policy associated with political correctness. To put this another way, you can’t really trust what is pasted on the motor or printed in the owner’s manual.
Of course, it’s desirable to use the minimum amount of oil necessary to protect the motor. Most OMC motors with rolling element bearings on the mains and both ends of the rods should be OK at 50-1 (but I expect to get jumped on for saying so.) I would personally not run any motor at 100-1. Most motors for which this was advised can tolerate *running* this mixture, but there is no margin for error in mixing and inadequate protection in storage.
Most 2-strokes used in ultralight aircraft, where you *really* do not want the engine to fail, seem to use 50-1.