2000 mercruiser 502 mpi
 

502 mpi engine floods or smells to be flooded and will not crank for a couple minutes after a hard run and 30 to 45 minute break. Have changed the map sensor and can not see any fuel in the fuel pressure vacuum hose. Any ideas? Could it still be the regulator or is the fuel in the vacume hose obvios if bad?

Aren't you concerned about the no crank situation too ?

If you mean won't start, search vapor lock

If you think its flooded and it cranks over but won't fire try holding the throttle wide open while cranking. This should turn off the injectors and it should fire up.