Slightly off track, but:
I worked at Off Road Imports in 88/89/90, then again a few years later. They were the Maico importers for many years, and Ross King who owned the business had worked at the factory when he was younger ( I loved the stories about how the factory canteen sold beer, and blokes would put it into the ovens that heated cases etc for bearing insertion so it would be warm for the breaks......... it seems, given responsibility, the workers never did what you'd think, and get rotten over lunch).
Any way, Herbert Schek (sp?) and his daughter contested the Dakar on Maicos in 89 / 90? , and after they had retired (his daughter broke her arm, and Herbert was there to support her) he spoke to Ross and revealed their biggest mistake.
That was, to fit giant main tanks and pannier tanks. The bikes, even with the weight of the huge fuel load, were so much lighter than the big 4t multis that still dominated at the time. This, combined with their power and torque advantages, meant they didn't use anywhere near the amount of fuel that people thought they would. So they were stuck with the unwieldy bulk of the big tanks they thought they had needed. Herbert said, that if he were to ever try it again on his Maico, or any 2t, he'd set it up with much smaller tanks.
Honda made use of the lighter weight, and better power / torque ratios of the 2t, compared to the big , heavy 4t twins and 4s (Yamaha, for a while), when they got 5th (?) outright with their 400cc EXP AR cylinder bike. They did win with the 4t twin, of course. When you're hammering anything, it tends to really use juice. Schek reported that whilst he and his daughter could be using the mid range, and lower revs, even the big 4t multis were screaming their guts out to get through the sand etc.
When you're caining a 4t, it tends to use juice much like a 2t does. It's the inefficiency/ loss of unburnt fuel, of the 2t scavenging process that hurts it so much, especially at lower / steady revs. These inefficiencies, are easily overcome by DFI, or simpler, AR / AST technology.
My 500 regulary uses exactly the same amount of fuel that 4ts use on rides. In fact, it quite often uses less.