17 1/2 gallons (66 liters) of external fuel capacity. I ran as much fuel out as I could, about 16 1/2 (62.5 liters) of the supposedly 15 1/2 (59 liters) gallons that were supposed to be remaining in the fuel tank. There still was some unusable fuel left in the tank. I then put the fuel back in the tank through a filtering funnel. Once all the fuel was back in the tank, I ran all of it out again and put it back through the filter funnel. So the fuel has been through the fuel line filters and filter funnel twice.
I measured fuel flow with 1 pump at 5 gallons in 8 1/2 minutes for a rate of a bit more than 35 gal/hr or about 133.5 lit/hr. With 2 pumps at 5 gal in just under 6 minutes the rate is about 50 gal/hr or 189 lit/hr. Plenty of fuel flow and this was with the cruddy filter.