Why Your Boat Won’t Start

The top 25 reasons your boat motor won't start, and how to fix them.
Boats at the dock
Even the mood created by this idyllic scene can be ruined by a hard to start marine engine. Boating

Check out this list of 25 reasons why your boat motor won’t turn over or boat engine won’t start. Don’t spend your time aimlessly poking and prodding; instead use this list to help identify the problem. Chances are the answer to your boat engine problem is somewhere on the list. Or, at the least, the list will help you identify the actual boat engine problem you’re experiencing.

1. Empty gas tank
2. Gas tank air vent not open
3. Fuel lines kinked or severely pinched
4. Water or dirt in fuel system
5. Clogged fuel filter or screens
6. Motor not being choked to start
7. Engine not primed — pump primer system
8. Carburetor adjustments too lean (not allowing enough fuel to start engine)
9. Timing and synchronizing out of adjustment
10. Manual choke linkage bent — auto choke out of adjustment
11. Spark plugs improperly gapped, dirty or broken
12. Fuel tank primer inoperative (pressurized system)
13. Ignition points improperly gapped, burned or dirty
14. Loose, broken wire or frayed insulation in electrical system
15. Reed valves not seating or stuck shut
16. Weak coil or condenser
17. Cracked distributor cap or rotor or shorted rotor
18. Loose fuel connector
19. Poor engine or ignition ground
20. Faulty ignition or safety switch
21. Low cranking speed
22. Low voltage to ignition, when cranking
23. Low Compression
24. Safety Lanyard/Kill Switch disconnected

Takeaway: If your engines won’t start, don’t just keep cranking the ignition or you’ll drain your batteries and add one more thing to the list above.