I wonder what 2T oil and mix ratios are being used by those riding 2T trials bikes? There seems to be an awful lot of confusion over this, with many people using low smoke autolube oils at the type or ratio's that should really only be used when fully synthetic PRE MIX ONLY oils are in use (80-100:1). All JASO approved oils are low smoke, and most include up to 20% kerosene to thin the PIB additives used to reduce smoke, so clearly are not actually "fully synthetic" which is often claimed by manufacturers. No problem at all using one of these oils as long as you dont mix any leaner than 50:1, other than the fact they are very thin and will not provide the same level of corrosion protection as a proper pre-mix only product, designed for use in competition machines. Running 50:1 mix tends to clog exhaust systems pretty quickly, and throttle response isnt as good as with leaner mixes, so it seems a good idea to use a proper pre-mix only oil at 70-80:1 on air cooled bikes, and 80-100:1 on watercooled, as this will mean better performance and less need to service exhaust systems so regularly.