Never been involved with a three wheeler old or new but messed with loads of m/cycles..... The guys who have already commented covered the expected oil in sump after lay up situation, the only other suggestion I might have is once you have put the oil back in the tank, remove the spark plugs and spin the engine over to give the oil time to recirculate around the engine.... However if there is a fuel pump, I might pull it`s relay. and disconnect the power to the coil to kill the sparks... I am not keen on firing up engines on which the lube may have drained down during lay-up..