CD25D fuel level

[wikakaru]

I have never heard of such a device – a fuel whistle! I always refuel from a jerry jug via a Racor funnel. My guess is that the flow rate through the filter would be too slow to generate enough air passage for the whistle. Any thoughts on this?

Great idea though – I could have used this when I ran a power catamaran and saved myself a fortune in Dawn washing up liquid.
Ed

I think you are right that if you use an external pre-filter, the flow rate would be too slow to activate the whistle, plus a lot of air would probably come back up through the fill opening, also bypassing the whistle. I remember how slow my Baja filter was. A fuel whistle will work best if you are fueling directly from a marina fuel pump.

Keep in mind that a fuel whistle is only a "quick and dirty" solution to the problem mentioned. A much better solution is to move the vent to a location that is significantly higher than the tank fill and easily visible from the tank fill location. On one of my previous boats the diesel fill was in the cockpit sole, and the diesel tank vent was at the highest vertical point in the bridge deck, so there was about an 18" vertical distance between the two. Even so, the vent would still overflow first, I suppose because the air coming out the vent was at a fairly high velocity and the air bubbles escaping the tank would burp fuel up out of the vent. I would hold a fuel "diaper" under the tank vent, and when I got the first burp I knew it was time to stop filling the tank. Not all boat designs will accommodate that configuration. Short of that, filling the fuel tank may need to be a two-person operation, with one operating the nozzle, and the other at the vent holding the diaper and monitoring the progress.

Smooth sailing,

--Jim

[Steve Laume]

The height of the fuel vent is not important except that it should not be the highest point in the vent system. You need a high loop in the vent line so that any water that would make it's way into the vent would drain back out and not into the tank. A small amount of fuel would do the opposite and drain back into the tank There should be no dips where fuel or water could settle. The vent was never intended to act as an overflow.

I use a siphon or a small nozzle at fuel docks. I can't control the flow rate with the siphon but will just barely squeeze the trigger at a fuel dock. I never trust the fuel gauge. What I do is listen very carefully. That means no music or conversation while I am fueling. I get close to the fuel fill and never create so much flow that air cannot also escape at the fill. Once you get an idea of what it sounds like when the fuel just reaches the filler pipe, it is easy to stop before it fills the vent and contaminates your surroundings.

Go slow and listen carefully, Steve.

[n5ama]

My CD25D has a fuel gauge on the port side of the tank. There is a small door on the inside of the port lazarette for viewing the gauge. I believe capacity is 8 gallons.

Bingo!!!
I've also got the door on the port side and that was where the "little gauge" was hiding.

I also calculated the volume in the tank to be about 13 gallons. Of course, this was while I was jammed between the engine and the overhead checking the gear box oil level. It's a tight squeeze and my steel tape measurements were probably not very accurate.

Thanks to all for the help.

[Dick Kobayashi]

Forget the impossible to get at and read gauge on the tank. 1) be sure to fill up in spring, 2) keep a log of the approximate hours of engine run time (easy if you have an hour meter, but penciled approximations are fine), 3) remember that the consumption rate for 1GM is about 1 liter per hour, 4) make reasonable conservative estimates, and 5) tank up when ever/where ever it is convenient.

If anxious or looking for confirmation or bored - use the stick. btw using the stick a few time will check your calculations and make you more confident in them. Then you can throw away the stick.