You need a 'starter rock' lol
first, i hope the car your jumping it to wasn't running. NEVER jump a bike off a running vehicle.
are you jumping it correctly?: pos to pos, both vehicles, neg on car at battery, neg on bike to engine or frame good ground point (no paint). not to batt neg. this must be the last clamped hooked up.
Starter could be full of oil, try tapping it with a hammer (don't whack it!) the starter is on the bottom front of the engine, behind the ft exhaust pipes & below the radiator.
how old is the battery? it may just be too dead to charge. hard to start even by jumping.
--Lucky