Help with motor please!

[paragod]

Sounds Ike your pretty Mechanically inclined unplug the main wire harness at the engine with a starter button on the starter solenoid crank it over and check spark again this will take the boat out of the picture. If you have no spark on all 3 it is most likely the Stator switch box usually drops one cylinder not common to drop all cylinders

[HoustonTexas]

This is on a suzuki df 140
(No spark)
Blown fuse for ignition system. Replace.
Loose connection or disconnection of
lead wire.
Connect securely.
Faulty spark plug(s). Replace.
Faulty ignition coil. Replace.
Faulty CKP sensor. Replace.
Faulty CMP sensor or sensor trigger
vane of camshaft.
Replace.
Faulty Ecm