.030" Champion L4J (L86C) or NGK BR6HS
.030
The spark plug gap for a 2003 Mercury 125hp outboard motor is .040"
A Mercury outboard will run well with a plug gap of .035 - .040 in.
The correct spark plug gap for the 1982 model, 9.8 hp Mercury outboard is .040 in.
spark plug gap for a 1996 mercury 30 hp outboard motor?
What is the correct spark plug gap setting for a Mercury outboard 2003 200 HP EFI
What is the spark plug gap for a 9.9hp mercury outboard motor
NGK BPR6HS-10 spark plug. Gap is .040
Johnson 6hp spark plug gap
The 25 hp Johnson outboard runs a plug gap of .030 in.
The plug gap for a 1995 model, 85 hp Suzuki outboard is .039 in.
The recommended spark plug gap (per NGK) is .039"