Re: Gas/Fuel ratio for a 1964
I run mine on Amsoil 100:1 pre-mix @ 2 oz per gallon, however that works out to 64:1. In '64 OMC went to needle bearings in all the outboards. They were trying to catch up with Mercury's bearing technology. My 1965 has thousands of hours on it @ 64:1 and still has the original head gaskets. It has never tasted alcohol or salt water and always run in Oligotropic lakes, meaning clear and cold. Carbon deposits from petroleum oils @ ratios of 24, 40 or 50:1 will raise compression, build back pressure and cause predetonation, higher combustion temps, overheating and lead to other issues like head gasket failure.
If a quality synthetic is used in an older motor, I might recommend evaluating carbon accumulation first then might remove/replace head gaskets and clean up carbon. If your older motor has its original head gaskets, it might be a good idea to replace them anyway. Don't forget to clean nicely the threads and use a little anti-seize on the bolts. Take good time to clean aluminum head/block surfaces in order to not cause harm. A gasket removing spray is highly suggested...........then again just keep your 48:1 and hope for the best. Regards, Tim
