Octane differences

[Capt Terry]

I used Amoco high test in my high compression Corvettes in the 60s - 80s because that was how they ran the best. It was also recommended in the Merc owner's manual, so I used it in my Merc 2 cycles from 1976 until maybe 2003, when I started having issues and discovered even the Amoco high test had ethanol. My issues- very hard starting & initial running following a lunch break of trouble free running in the morning, almost like vapor locked. The fuel bulbs would not stay firm and I tried several bulbs, replaced fuel lines, and on & on. Sometimes had to use starting fluid to get it started. My problems disappeared when I started using real gas as recommended by a Merc mechanic, who also suggested I mount the bulb vertical. A friend who burned up two 2 cycle engines on weedwackers was told by his mechanic to only use real gas in 2 cycles. I've had an ETEC for two years which is supposed to be ok on ethanol- but I have stayed with real gas.