That's what those gears for...
I saw a pic in the 70's where there was a storm that knocked out all power. They took the door panel and side panel off the cabinet and had taken the rear tire off a bicycle and had a long fanbelt from the pump pully to the rear wheel of the bicycle.

Veeder Root Rebuilds.....since 1987
Veeder Root Identification CD
Gas Pump Clock Repair
jkyocom@bellsouth.net