If your carbs are pre monobloc. move the floats forward of the mixing chamber. This may help, it did mine, but only on the right side stand!. (P. Richardson recommends this in "Vincent Motorcycle"). For the left sidestand (the one I actually use) tickle the left float until the engine just falters a little and then your good for 10-15 seconds leaning it over on to the left side stand to raise the rear stand up in it's stowed position.