When changing the spark plugs of a vehicle a person has to gap the plugs at the right size. The spark plug gap for a 2003 Heritage Softail is .036 inches.Ê
.40
.038" to .043"
.040 or 40 thousandths
.040
The 2003 Harley-Davidson Heritage Softtail transmission drain plug is on the bottom of the transmission. The drain plug is flush with the bottom of the transmission. You can remove it with a half inch ratchet.
.037"-.043" using any spark plug gap gauge. I have a 93 heritage softail classic and that is what is recommended.
Use a dime to gap the plug. If u haven't got a dime use two nickles
The spark plug gap for a 1994 Harley-Davidson Softail Heritage is typically set at 0.040 inches (1.0 mm). It's always a good idea to check your owner's manual or service manual for the specific model to confirm this specification. Proper gap adjustment is crucial for optimal engine performance and efficiency.
.040"
Twin Cams take a 12mm thread diameter plug. All Harleys with electronic ignition require a .040 plug gap.
.40
When changing the spark plugs on any vehicle, the person must leave the right gap size. The 1999 Harley Softail has a spark plug gap size of .040 inches.