Had the boat for about a year now, and I usually fill up gas when it gets to about a quarter of a tank, just for my own comfort. The rated fuel capacity is 49 gal, but at the quarter tank level I can only get 20 gallons in it. Is this type of inaccuracy typical? Does anyone know what or where the best place to get the gauge calibrated?
2110 NauticStar ShallowBay
150 Yamaha
Sounds right , I have a nautic star 2000xs last time I filled up it was on 1/4 tank took 46 gallons. I have a 75 gallon tank. I once ran it till it was sitting on the bottom and it took 66 gallons. Must be a nautic star thing.
Not unique to Nautic star. I have a brand new boat and gas gauge is off. It registers 3/4 tank when tank is filled to almost over flowing. Registers empty when 20 gallons left in a 58 gallon tank. I guess that will keep me from running empty.
gas gauge on a boat is notoriously inaccurate
at best it is a rough guide
angle of hull can change fuel reading by as much as half
Yes, This is an indicator at best. My new bay boat is the same way. I even had the dealer change the sending unit and test the gage for proper function. I have a 60 gal. tank. When it indicates 1/4 I pack it full with 20 gal. I agree with a previous post at least we will not run out if we fill it shortly after it hits ‘E’.
Most times I let the boat settle in the water just to see how close the gage indicates like Chris mentioned.
Get a flow meter. Chris put one on my boat a few years ago and it works great. It’s nice to know EXACTLY how much gas I have in the tank…
How does a flow meter show you how much is in the tank? Wouldn’t that just show you consumption while its running?
2110 NauticStar ShallowBay
150 Yamaha
Best fuel gauge I have found is a stick!! Had a 200 Gal tank made for my boat and had a fill inlet welded in the rear under a hatch. When I first filled the tank I marked a stick at every 25 gal. and made a duplicate, Its never been wrong! When the stick is wet at the 75 gal mark it has 75 gals. I also did the same on my whaler!
quote:
Best fuel gauge I have found is a stick!!
Amen to that! I used sticks for years on my charter boats, but not many boats are designed with a straight fill pipe to the tanks.
The problem is, most builders don’t calibrate the float on the sending unit. The tanks are custom built for them to fit the space and the sending unit is generic. It has to be custom fit to the tank. It is adjustable both in vertical height and the length of the float bar. It must be fit so that the extreme bottom position of the float is at the bottom of the tank, and the extreme upper position is at the top of the tank.
It takes some time, trial and error to get it just right, but it can be done. The float arm needs to be mounted athwartship, not fore or aft. This prevents bad readings due to boat trim. If the float is mounted to the rear or the front, boat attitude greatly influences the reading. Strange that half the boat builders haven’t figured this out yet, or don’t care if they are right or not. Mine read right 
Capt. Larry Teuton
Cracker Built Custom Boats
“Ships are the nearest things to dreams that hands have ever made.” -Robert N. Rose
quote:
Originally posted by bearcataslHow does a flow meter show you how much is in the tank? Wouldn’t that just show you consumption while its running?
2110 NauticStar ShallowBay
150 Yamaha
You have to manually enter the amount of gas you put in the tank each time. You can toggle between flow and total gas in the tank while running.
My boat takes 150 gal and depending on the angle of the forklift at the marina, it will take ±10 gal. That means that I always assume I’m running with 130 gal when full and I always reset my Yamaha command link computer before each trip so I know how much I have left. The computer is extremely accurate as far as fuel burned goes. Normally within 0.5g out of 100g.
26 Seahunt
Angler’s Dream