How much usable fuel in 25 gal tanks

[breausaw]

How much fuel is supposed to be left in the tank when you run it dry? A couple of weeks back I ran my starboard tank down to the point the motor sputtered and had to switch over to the port tank. I figured there was a little over 3 gallons of fuel left in the tank, based on how much it took to fill up and visual inspection. So wondering if this in normal, I guess if I dropped back to displacement speed the fuel would flow forward and the pickup tube would pull out more.
Suppose I could pull the pickup tube and make adjustments so it pulls from the back of the tank.
I usually try and have 1/4 to 1/3 fuel in main tanks on returning to port just for safety, but in the event I’m in a situation where every last drop is required I’m screwed.

[Jeff Brigner]

Looked at your Triple J projects album. As handy as it appears that you are I'm surprised you don't build some sort of gyro device that keeps your tanks level at all speeds.

Nice looking boat

[marvin4239]

The tanks in my 2007 22 are actually 23 gallon tanks. I think the c-dory brochure said 25 but if you look on the side of the tank it says 23 gallon. I too have what appears to be about 3 gallons left when operating at cruising speed but at displacement speed you can get it down to about 1 1/2 gallons.

[Sea Wolf]

I think we've seen quite a difference between boats built over the years in terms of how much fuel remains in the tank after the pick-up goes dry.

I ran my 18 gallon tanks down once to find out, and found that they took 17-1/2 gallons to fill! Others have had varied results, with some reporting as many as 4-5 gallons remaining in 25 gallon tanks.

With your 3 remaining of 25 gallons, you're leaving about 12% of the fuel in the tank.

I'd think it prudent in one respect, that of safety in having enough gas to get home, that the tanks be drawn down to the last gallon or so.

On the other hand, with the E-10 alcohol gas mixture so common now with it's propensity to collect water, that one wouldn't want to draw too close to the bottom of the tank, so maybe leaving 10% or so on the bottom isn't such a bad idea after all!

If you do go for the last gallon or two, carrying a spare filter would be a must (I think it is anyway), and cleaning the tanks and using a water removing additive periodically would be good ideas.

Joe.

[flrockytop]

My 2007 CD22 tanks are marked as 23gal. My CD19's were 25gal. On my first 1600 mile leg of my Super Loop I would run at displacement speed and alternately run the tanks dry. When I did this there was 0 gas left in the tank and it took 23 gals to fill it back up. I ran one dry at cruise one time. I did not think to check and see if there was any unusable fuel in the tank after that. Running out at cruise caused other problems. I was not able to get to the back and switch tanks before the engine quit. Because the engine was running at 4100 and stoped immediately so did the water pump. The over temp alarm went off and the computer put the engine in "limp" mode.

Roger

[tomherrick]

Don't mean to hijack this thread, but on the subject of tanks I'm looking for the 23-gallon model C-Dory uses for the 22-Angler models. Moeller makes a 23-gallon tank and the factory (the Fluid folks) said they used the Moeller tank. But, a friend of mine has a 2007 Angler that has tanks that slope in on top toward the transom and I've not been able to find those through Moeller. Anyone know the maker of these tanks?

Thanks,

Tom Herrick

[breausaw]