I have a 1994 Mercury Black Max 200 HP carb OB and have always used whatever gasoline the local Costco sells, regular, not premium. Sometime gas will sit in my shed in 6 gallon jugs for months before it gets used. The only additive I use is marine Stabil per the manufacturer's directions.
I read that not decarbing an outboard can ruin the powerhead if a ring sticks. I idle a lot and but also tow wake boards, tubers and skiers as well. So the engine gets a variety of uses although is not use a lot. I have about 200 hours on it since 1994.
For an engine this old, it runs remarkably well. The oil injection plastic drive gear is shot so I now premix, 50:1 Mercury non-sythn oil I'm wondering if I should fool with success. Should I be running premium if it runs ok on regular. Does synthetic oil carbon up an engine less than regular oil? Does the age of the gasoline have a significant bearing of the life of the engine. Are decarb solutions like Seafoam really necessary and can they be harmful if the engine has never been decarbed?
I read that not decarbing an outboard can ruin the powerhead if a ring sticks. I idle a lot and but also tow wake boards, tubers and skiers as well. So the engine gets a variety of uses although is not use a lot. I have about 200 hours on it since 1994.
For an engine this old, it runs remarkably well. The oil injection plastic drive gear is shot so I now premix, 50:1 Mercury non-sythn oil I'm wondering if I should fool with success. Should I be running premium if it runs ok on regular. Does synthetic oil carbon up an engine less than regular oil? Does the age of the gasoline have a significant bearing of the life of the engine. Are decarb solutions like Seafoam really necessary and can they be harmful if the engine has never been decarbed?