On the Water Trouble Shooting

Picture this; it’s a beautiful day to be out on the water, sun shining, calm breeze, birds working the water. My boat is all tuned up and running great. I made it out to my favorite location for some drift fishing.  Then it happened… nothing. I went to fire up the engine to move and it did not start, not even crank over! The things that through your mind as you try to make sense of this all.

This conversation is not all that uncommon. The intent of this article is to walk you through the steps that you can take to possibly get you up and running again. The process starts way back in the spring when it was “commissioned”. Today’s engines are full of complicated hoses, wires and computerized equipment. Believe it or not, it’s the simple things that usually ruin your day of boating.


Marine batteries have to be load tested to ensure they are up for the challenge. If you have to add water frequently to your batteries they are being damaged by overcharging. You’re charging or shore power system should be checked if this is happening.  Multiple starts drain the battery and smaller engines only have charging systems that will “trickle charge” the battery to a full charge. This is important if you drift or troll a lot of the time. What is not common knowledge is that most ignition systems create their own electric and are not dependant on a battery at all. Loose battery cables will not only prohibit the engine from cranking over but will also prevent it from being recharged. It is very important that all connections to the battery be clean and secured with “stopnuts” not the “wingnuts” that most are supplied with. While we are talking about batteries there are some Coast Guard regulations that have to be adhered to. 1, At least the positive post has to be covered with a rubber boot or the battery in a box so a metallic object will not come in contact with it. During a recent seminar we conducted, we were told of a boater whose metal fuel tank came in contact with the battery terminals… that was a very bad boating day. 2, Batteries need to be secure. At least a 90 pound pull from any angle and it cannot move more than one inch. Just yesterday I removed a single “plastic wire tie” about 25 inches long securing a battery on a 17 foot Boston Whaler.

Electrical system:

I truly believe that electrical departments in building supply stores would be impacted without the boating public. We are many times troubleshooting a voltage problem when we come across, lamp cord wire, electrical tape connections, and those pesky house wiring, “wirenuts”. These products do not work at all in a marine environment and are dangerous to use on a boat. Wiring has to be of proper size, proper terminals and secured at least every 18 inches. We have all been on a boat where it “Hits Hard” coming off a wave. Imagine the force transferred to loose hanging wires. We have seen this condition pull the wires off dash switches. Remember that extra 30 feet of transducer harness just hanging behind the dash panel? Marine wire and terminals are more expensive but they have a solder coating on all the strands to resist corrosion of the copper. Don’t forget that all electrical circuits have to be protected with a fuse or circuit breaker of proper size. You will now see that wire colors have changed in our twin conductor or “Duplex” wire. What was red for positive and black for negative has changed to red /positive and yellow for negative. A child was electrocuted as it was found that someone had connected all black wires together. This untrained person connected the “Hot” or “Live” wire from his 110 volt shorepower, which is black, to the negative ground on the 12 volt system. If you do not know or understand electrical systems have a Marine Technician perform the job. For the same reason it would be unwise for me to wire up a building, “Electricians” are not trained in marine electrical systems.

Fuel System:

Regular inspection and fuel filter monitoring should be part of your boating experience. The fuels of today do change rapidly. Old fuel in a modern computerized fuel injected engine just does not make sense. We have cleaned over 30 carburetors so far this season alone, so I guess it’s not good for older engines also. Only carry what you will burn in 4-6 weeks. Use a quality additive that will not mix the water into the fuel solution. That is like asking your filter to remove the sugar from sugarwater… it can’t. Your filter works best stopping 10 micron debris and leaving the water whole so it will settle in the bottom of the filter canister. Your main “Spin-On or Racor” is only one of up to 12 filters on some V-8 engines. Fuel contamination and filter restrictions are main causes of hard starting, stalling and general poor running engines.

Pre-departure checklist:

A complete and thorough inspection of all systems and safety equipment should be done every trip.

Getting back to our non-starting boat, we can see that there are a lot of ways to prevent these stories. How is one to know what system is not working? Here are a few guidelines.

If the engine does not crank: see if the gauges move when the key is turned on. Many have a voltmeter so that will help. A reading of about 12 volts is good. While holding the key in the crank position, move the shifter handle. Many times this is all it is. There should be some type of clicking on the engine. That is the starter relay and may not be too loud.

If the engine does crank: is there a safety lanyard or switch that could be tripped? This switch usually does not stop the engine from spinning. Is the engine cranking slow? A low battery or loose battery cables could be at fault here. Change your “Battery” or “selector” switch to another battery if equipped. Many systems will not charge the second battery if it is not in the “Both” setting. An inexpensive “Jumper Pac” is available in many stores and is a valuable asset if needed. Don’t kill the battery.

Check the contents of the main filter. Only if it is “full” will it pass debris or water to the engine. If this is the case, you can try installing new filters but the contaminants are already in the engine fuel system. There is little one can do on the water in this case.

Electrical items stop working:

Check fuses or circuit breakers. If the fuse blows instantly there is a short in the wiring and an inspection may show the problem. Wires pulled off switches… inspect if possible. Clean terminals-tighten contacts  as needed.