This is a slight deviation from the issue, but in looking for pictures of the fuel system and the carbon canister, I was not able to locate a FUEL FILTER that is replaceable. Well, fuel filter is a good place to start with on ANY engine that runs crappy.
On my F650 Dakar single it was there...built into the fuel rail pressure regulator...and FREAKIN $50!! But this F650/800 is a returnless system....plumbing is very different...all I can find is a $50 STRAINER on the fuel pump suction (inlet) side.
FWIW....look at the two micro fiche pictures of the fuel supply system (tank etc) and next to it the canister system....you'll be able to see the canister stuff that gets added after the fuel tank vent. Modern cars with canisters and such don't take kindly to liquid fuel getting into the canister as they don't purge liquid well...they are designed to suck up vapors on the carbon then purge them back into the intake....controlled by the engine computer.
I'm wondering if this stalling thing that can be traced to canister issues is because the canisters have been contaminated with liquid fuel from over fueling or tipovers! I'm just wondering if BMW did a crap job on the carbon canister system that is probably a US only thing. Say thank you California, CARB and EPA for this crap!