The bottom end bearings will run submerged in oil. They won't run very long dry. In saying that some people run with next to no oil. Some use heaps. Whats more important is using a quality oil and jetting to suit the ratio you use.
FWW most oil manufacturers will specify a ratio.
From
http://www.opieoils.co.uk/p-926-motu...mpionship.aspx
About Motul 800 2T Factory Line OFF ROAD Lubricant of MX 250cc World Championship
Lubricant of MX 250cc World Championship
Premix Racing 2 stroke Engines
100% Synthetic - Ester
Formula developed for Motocross Grand Prix Teams. Suitable with standard and unleaded gasoline up to 124 octane
All racing 2 stroke engines, high performance and using premix : Moto cross, Enduro, Trials, Quads, Watercrafts, Ultra lights...
For road bikes, use MOTUL 800 2T ROAD RACING. For oil injector systems, use MOTUL 710 2T.
RECOMMENDATIONS
Mixing ratio : MOTO CROSS GRAND PRIX : 2% (50:1). In normal conditions decrease the percentage by 0.5%.
Tune according to your own use.
So there you have 1.5% mix as stated by the manufacturer. 66:1 under normal conditions.