I just put in new NGK IZFR5G spark plugs during service, I do it every year even though runtime per season is down to 10-15 hours. This year I gapped them to 0.040 according to my service manual... They are 0.032 from the factory. What gap do you recommend?
Engine: 2006 Mercury Racing Optimax 200xs 15" SportMaster 1.87
Serialnr: 1E001692
Runtime total (hours): 132
Boat: Allison SS-2000 Excel
Prop: Mazco RE3 30p
Max rpm: 6800
Water pressure reading: 5-6 @ idle and 15 @ WOT
Instruments: SmartCraft
Engine mods: removed exhaust block off plate