Failure to do so will cause a rift in the space/time continuum,open a wormhole,and catapult the Earth into another dimension.Or at least cause erectile dysfunction.
That's very funny CommandoRdster
That such a relatively simple task generates so many posts, may illustrate our paranoia over being stranded along the side of the road. I do not have a Triumph twin, but a former Road Star and Royal Star worked the same way. I routinely changed to reserve on the fly to extend my cruising range and always placed in OFF to avoid the rare occurance of flooding the carbs. Only sometimes I would forget to put back to "ON" and have to change over a couple minutes later - again on the fly
My Daytona 1200 has a vacume controlled fuel tap which shuts off the fuel supply when the engine is stopped in the ON or RES position. So there is no need to ever touch it unless you need to use the reserve gas.