Re: What year is my Evinrude?
It'll be your choice on the mixture of course.
OMC did release a bulletin many years back that stated that "all" of their engines could use the 50/1 mixture excepting the 1957 7/5hp model..... and it was never explained fully to me why that exception existed.
However, as time went by, pertaining to engines with perfect carburetors, no fuel/air leaks, in essence no flaw of a mechanical nature that would affect the mixture..... I noticed that I was rebuilding many more engines that had the appearance (bearing wise) of running lean, and this pertained to only those engines that had the babbit type bearings. Engines that were equipped with all roller, needle, or ball bearings did not encounter this type problem.
So, although the above OMC bullletin existed, in time the general practice pertaining to the 50/1 mixture was to use it only on engines that incorporated needle, roller, or ball bearings on every rotating/moving part.
The 1964 5.5hp model has babbit type main bearings, hence my advice to stick with the 24/1 mixture.
It might last forever on the 50/1 mixture BUT is it worth the risk?
