OMC Stern Drives And Motors 1964-1986 Repair Manual., Page 33Get this manual
Dumage to this pilon was caused by obnonnal cornbustion because the be1 exploded violently, causing the spark plug, piston, mi valves to overheatProper adjustment qf the spark advance or change in fie1 higher octane rating may comect the problemTpicd titning marks
2-5 FUEL SYSlEM SERVICE
Genera1 Practices Change the fuel filter in the base of the carburetor at least once yearWhen the filter is changed, use new gasket under the nut prevent fuel from leaking out of the filterChange the water separator every yearClean the arrestor every 100 hours of operationN ADVANCE