fuel filling question

[Jim from New York]

I would like to know if anybody can answer a question about fuel tanks. My boat is a venture 23 boat has 30 gallon tanks and I did measure and verify the volume.

But from when the needle show empty to full always takes 20 gallons when time to fill up So I always plan trips for 40 gallons which I’m sure is not accurate.

Does anybody have the same condition I’m assuming the needle bottoms out with still 10 gallons remaining. Any input greatly appreciated thank you
Jim

[JAKE7746]

Try running on one tank until it is empty and when you flii it you will know

[NORO LIM]

My 23 also had two 30 gallon tanks. I purposely ran each of them dry. They each took about 27.5 gallons to fill. For long range planning purposes I always just assumed 55 gallons of usable fuel.

The tank needle gauges are often problematic. Mine was unreliable, but my Yamaha fuel usage gauge was pretty good. I also kept my own careful records of fuel purchases and mileage travelled between fill-ups.

[DayBreak]

Hi Jim,

We also have a 2018 23 Venture. I have the same issue with our fuel gauge readings as you but don't mind. In fact, I find it personally beneficial. When our gauge reads 3/4 tank, I have only really used about 5 gallons of fuel. When the gauge reads 1/2, I have used about 10 gallons. When it reads 1/4, I have used about 15 gallons and when on 'Empty', I have used about 20 gallons. At empty, I know I have about 10 gallons remaining in each tank. I plan my travel to never let the tanks go below 1/4 full even though I still have 30 gallons between the tanks which is plenty of reserve.

[ssobol]

Get a fuel flow meter, then you know how much you've burned and therefore how much is left in the tanks.

[hardee]

[Baxter]

Mine pretty accurate. Run two 50 hp Honda’s one tank at time.
Do distance cruising I fill wherever I can. We do Antacortes, WA to Desolation sound and beyond.
You can remove gauges in tanks but must pull tanks out to lift them out. Do when low on fuel they are heavy. Then I set guages by side of tank to see where float was. They were ok. If not can be adjusted manually. Cleaned electric contacts and replaced gaskets. They come in kit with new screws Etc Could also be Dash gauges themselves.

All that said I would invest in good flow meter as suggested in other post.
Check what the per cent of accuracy it has. Wish I bought one when I got the boat 7 seasons ago. I am nearing the end of boating career so don’t want to spend the money.

You can also do time knowing per hour fuel consumption. But lots of variables where we cruise. Probably average 4-5 gallons per hour. But there are variables
Wher I cruise. Strong tides, winds. Speed cruising. Rpm , Weight on board.

Good to leave 1/3 reserve but often I am at 1/4. Once when far north
A place that Was to have fuel did not any longer so eased back on throttle and
Made it back to Refuge Cove withb15 galleons. left. Relief.

I burn only corn free gas high octane fuel. Alcohol has no business in gasoline. Stuck however on Chesapeake Bay as illegal to sell alcohol free in MD.

I do not like running takes dry.

I carry a 6 gallon spare tank the will at least get mr to shore. Has hose with Honda connector so can run one engine.

Long story. I would invest in good flow meter.

Most I learned about fuel mgt. was from flying airplanes. So I switch tanks to keep boat balanced.

Happy cruising.

[Desert Dory]

Jim,
I see your boat is a 2018, so I'm going to assume your engine/engines are right around the same year.

Having said that, most newer engines have a port on them to connect a NMEA 2000 harness to gather and display, usually on your MDF/Chartplotter, pretty much any engine data you would ever want to know, including fuel flow.

Initially, you will have to program your MFD with your fuel capacity, which should be easy. Once you do that, you just tell the MFD how much fuel you added when you get gas and it will compute the rest.

Example: My ETEC 90 is an '08 and has the NMEA port on it. I bought the correct harness, $60, and now have it tied into my Garmin chartplotter. When it comes to fuel, mine will display fuel flow rate, MPG, distance/range left before empty, etc, etc, etc...

My tanks hold 36 gallons total. When I initially set up my Garmin I told it I only have a 30 gallon capacity. Since I have never run the tanks to the point the engine shuts down, I really don't know my true "usable" capacity. Hopefully this strategy gives me a bit of reserve.

Besides fuel info, it will also display RPM, engine hours, water temp, oil temp and oil pressure (if mine wasn't a 2 stroke), and a host of other things.

It's really pretty cool, and useful. And, if you already have a NMEA buss set up on your boat, I'm willing to bet you probably just need the proper cable for your engine to tie it all together.

[Jim from New York]

I hate to run thanks empty but at the end of the season I’m going to run engine till it cuts out. Later I will fill up to verify the tanks take 30 gallons I’m sure that will be the case. I’ll post what I find
I’ll be changing the fuel filter end of year anyway.
Thanks again for all of your input
Jim

[thataway]

There is controversy about empty tanks agains full tanks. It is permissible, especially in the cold weather areas, to empty the tanks. Plastic tanks seems less susceptible to condensation than the metal tanks. If you have ethanol fuel there will be phase separation, even with Stabil and Startron treatment.

It is also best practice to fog the engine, if you are going to leave it for a number of months, change the oil before storage, and service the lower unit. Also for injected engines, I like to have some injector cleaner in the lines when running them out.

Changing the filter is a great idea also. I much prefer non ethanol fuel if possible.

If I put NMEA 2000 information from the outboard, I like it on a separate display or a line on the largest chart plotter, which allows the radar, map or sonar of that display still usable. Some of the larger boats with multiple screens use a dedicated MFD for engine and other data. There is also the possibility to use an older MFD for engine display.

[Jim from New York]

I wanted to share information on gas gauge dilemma .I made a nice trip this week for a few days put on some miles. I ran port tank way past empty needle on fuel gauge. Didn’t want to run it totally out and shifted to Other tank after awhile. Filled tank back up and it took 26 gallons. So it’s safe to say 30 gallons is tank size, this will be fine information to plan trips for me glad to put it to bed. I’m sure I few have the same problem.

If anyone wants to speak to a new dilemma I’m experiencing I would welcome the advice here goes
My mpg were great at 4.5 mpg can’t ask for more then that and my top speed is always around 39/40
The 150 Honda rpms max out at 3900 (that’s my concern)
The specks show much higher 5000 to 6000. I’m happy with performance but should I be concerned with such low RPMs any advice appreciated all factory set up no modifications .
Thanks Jim

[tsturm]