Avoid spills. Slowly open fuel filler cap. Do not fill above bottom of filler neck insert, leaving air space for fuel expansion. Secure filler cap after refueling. Gasoline is extremely flammable and highly explosive, which could result in death or serious injury. (00028b)
Use care when refueling. Pressurized air in fuel tank can force gasoline to escape through filler tube. Gasoline is extremely flammable and highly explosive, which could result in death or serious injury. (00029a)
Installing Fuel Filler Cap

WARNING
Do not use aftermarket fuel caps. Aftermarket fuel caps may fit improperly and leak, which could lead to death or serious injury. See a Harley-Davidson dealer for approved fuel caps. (00034a)
NOTE
The arrow on the cap points to an index tab on the cap. The index tab aligns with a slot in the fuel opening in the tank.
Ensure the key is fully seated into the cap prior to re-installation.
Install the fuel filler cap with alignment arrow (1) pointing toward the front.
Press down around the cap to compress the cap spring. You may hear 2 audible clicks as the cap locks in place.
Turn the key counterclockwise to lock the cap and remove the key.
Figure 1. Fuel Filler Cap