by Kevin Falvey (original link)

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.

There are two ways we get water in our gas tanks:

Condensation: is formed when you have air inside of the gas tank,
and that air heats up with the sun. In the old days, the rules of thumb
was when you took the boat out, when you came back, you topped off the
tank to eliminate any volume taken up by air. But, in today’s boating world, this is not logical unless you’re more than an active boater. Why?

Ethanol alcohol. Ethanol deteriorates after 30 days. When you fill up a
tank with today’s gasoline and leave the gas sitting there, it loses the already-low octane ethanol has. In today’s world, most boaters don’t top off their tanks. Instead they estimate the range of their trip and add only enough fuel to cover the trip, plus a margin of safety. By doing so, they create the space in the fuel tank for air to fill, and create condensation.

You can also buy gas with water. The same condensation principles apply to a 200 gallon tank on your boat as much as a 20,000 gallon tank underground at pumps in marinas in larger scale.

Add a fuel treatment that will eliminate the water and break up the
contaminant that builds up at the bottom of the tank on a regular basis
(every time you fuel up).
*We stated that a filter that has a clear bowl on the bottom where you can see the water accumulating is not coast guard approved below decks. However, with outboard installations, this is not a problem.

We mentioned that water accumulates in fuel tanks because of
condensation, and how the best solution for this (topping off your tank) is impractical in today’s world because of ethanol. If you are having these kinds of issues that need attention, or if you wish to install a water separator, feel free to call us at 305 866 6636 anytime. We will give you an estimate on repair costs and will be glad to do business with you.

In future posts, we will talk about diesels engines extensively.