A tank with a 17-18 liter capacity is my minimum if I'm going to pay for an upgrade. Better would be 22-25 liters - fuel would be carried lower; and you don't have to keep the tank full. Just getting the bike here is the first step. If the quality is good, then I can build from there. Otherwise I'll have to start from scratch on something else (e.g. EX300R).
1990 Honda NT-650 Hawk-GT
Never doubt that a small group of thoughtful, committed citizens can change the world;
indeed, it's the only thing that ever has. - Margaret Mead