diesel tank filling on Catalina 27

[Bob Middleton]

I recently bought a Catalina 27 and after several hours of using the diesel engine, the fuel gauge didn't appear to move. My first thought was that it didn't work. However, filling the tank at the marina showed that the gauge was correct. The M18 engine simply doesn't use much fuel. Great! My question is how to know when the tank is full and avoid any spillage overboard. As the fuel nossel doesn't go far enough into the filler hole, it will not shut down automatically like for a car. Can you leave the ignition on to read the gauge as you fill the tank? Obviously not with a gas engine but how about a diesel.

 

[Tom]

Filling diesel tank

I have a C30. I can tell when the tank is reaching full by the way the gurgling sound from the fill tube changes pitch. When the sound goes away, fuel has started backing up into the fill hose (or vent hose) & it's time to quit. There are some owner-installed fuel tank vents available that are designed to whistle, and when the whistling stops, the tank is full. There are also some overflow containers sold at marine stores (e.g. West Marine, Boater's World) that have suction cups & can be placed on the transom over the tank vent (temporarily during filling) to prevent overflow into the water. The tank vent on the transom is usually lower than the deck fill, so the fuel will back out of the tank vent before it backs out of the deck fill. But after fueling a few times, you will notice the tank fill hose gurgle noises and how the sound changes as the tank fills. When the tank's close to full, the sound diminishes.As far as keeping the switch set to "on", some systems will activate the electric fuel pump with the switch on. I would not recommend having the switch on while fueling.

 

[Don]

Common problem on the 27

Mine is the same. The gauge reads off scale high until I use 4 gallons then it starts to come down. At 1/2 tank, it takes 9 gal to refill. You will get the hang of it after you have had the boat a while. The M-18 uses slightly more that a quart an hour. I write down my engine hours when I buy fuel. Divide hours since last refuel by 4 and that's about how many gallons it will take. With the vent lower than the fill port, it is very easy to vent fuel overboard and you don't want to go there.