Honda BF75D Owner's Manual page 123

If the engine fails to start, remove the
spark plugs and dry them, then
reinstall the spark plugs and attempt
to start the engine again.
If the engine starts and no mechanical
damage is evident, continue to run the
engine for a half hour or longer. Be
sure the water level is at least 2 inches
(5 cm) above the antiventilation plate 
to avoid overheating and water pump
damage.
7. As soon as possible, take the
outboard motor to an authorized
Honda Marine dealer for inspection
and service.
TAKING CARE OF UNEXPECTED PROBLEMS
121