They stopped at the tavern to take on fuel.They went inside to take fuel on and then came back out to watch the horses.
take on fuel
Of a vehicle or vessel, to have its storage of fuel replenished; to be refueled. The car pulled into the pit stop to take on fuel and have its tires replaced.With its tank dangerously low, the jet was forced to take on fuel midflight.
take on fuel
tv. to drink alcohol to excess. They stopped at the tavern to take on fuel.