wouldn't crank if it were the kill switch or kickstand/neutral or clutch safeties.
with your tossed plug against the head and plugged in, check for spark.
check for fuel, open drain with a clear line on it, hold the bike vertical and set the petcock to prime, should come up the bowl gasket or close to it. and then lets some drain into a gas can to see how well it flows. (see there... combined 2 tests in 1
)
then check for air... got any?
how white is the air filter?
is it wet?