The spark plug gap for a 2003 Mercury 125hp outboard motor is .040"
spark plug gap for a 1996 mercury 30 hp outboard motor?
NGK BPR6HS-10 spark plug. Gap is .040
.035"
spark plug gap for 5.0 liter engine is 0.054 inches
.040
.40
0.25mm
is 54 gap for a spark plug mercury mountanier 2002 4.6
.040
The year of the motor is 1985? Then it is not a Mercury Force. Also with the plugs that it takes, there is no gap adjustment,
The 1991 Mercury Marquis spark plug gap is .034. Most spark plugs will be pre-gapped by the spark plug manufacturer.