- Talk to the Machine Outfitter and choose "Assist with upgrades."
- If this option isn't available, you do not have enough fame or have already completed a quest from the Machine Outfitter in your current visit to Abyssea. You may have to do a few quests after getting reputation 2 before being eligible for this quest. I believe you also have to wait a game day between the previous quest and this one.
- You will be given the Fuel reservoir key item. Proceed to any martello (fuel supply doesn't matter), and choose "Upgrade the martello."
- Choose "Upgrade from the <X direction>." The direction in this option seems never to change in a particular run of this quest, regardless of your actions or the direction you were told to upgrade from.
- It is not necessary at all to obey the direction you were told to upgrade from.
- You will receive a Cracked fuel reservoir, with no log message. Take that back to the Machine Outfitter to complete the quest.
- Machine Outfitter (Central Encampment, Abyssea - Tahrongi)
- Upgrading the fuel capacity of the martellos in the Tahrongi Canyon will mean less frequent replenishment runs, easing the burden on resistance troops in the area. Install a fuel reservoir in a martello, and return the excess parts to the machine outfitter when the job is done.