Clutch drag, could be caused by a few different things:
1)Cold weather raises viscosity of gear oil/grease, causes mainshaft to stick to the output shaft,
2)Clutch cable bowden tube not adjusted to take out the slack, need to adjust it.
3)Clutch rod adjustment screw under the small cover on the gearbox is too loose, need to loosen the adjuster locknut, screw the adjuster a few turns clockwise until the cable slack removed.
4) Cold weather cause lube in the primary case to be more viscous, causes the clutch plates to stick together. Needs warmer weather or lighter oil.