fuel gauge issues doesn't read correct

[skinny1965]

ok so found out gauge is wrong guess how bad on me
anyway I cleaned the connections few weeks back. thought it was good but seems to not read correctly on EMPTY
do they set the float at empty with boat level or is there an angle the hull should be

 

[ihearth2o]

Hope you figure this out and share. I've been trying to figure out my fuel gauges for years. I learned to just not trust them anymore and have gotten into the habit of filling up anytime my gauge reads half full.

 

[inthedirtagain]

Considering that my daily driver is a 1966 Ford and my boat is a 1969 Silverline, I'm gonna go out on a limb and suggest that my crap is older than most folks. That being said, several of my factory repair manuals state that the gauges are adjustable (0 +/-). One of them gave a detailed description on how to set a true zero, but it required removing the gauge from the console and removing the sending unit from the tank. There is supposed to be an adjustment screw on the back of the gauge to set ZERO, but you will need to take into consideration of how level the keel is. Basically, I'm not sure how to exactly do it!

 

[thumpar]

My gauge stays pegged past full until the tank is down to about 2/3 and then will swing a little. When it starts swinging a lot I know I am at about 1/2. The tanks on most boats are shallow and with the movement on the water they don't work well. I have thought about putting in a fuel flow meter.

 

[tinman4u]

The fuel gauge will bounce.
If it makes you relax more use a stick, fill your tank and mark the stick at the top of the wet line, when the gas needle starts to act up use the old stick gauge then you know how much is in there for sure.
Here's a rule of thumb 1/3 tank out 1/3 tank back in and keep 1/3 emergency reserve

 

[skinny1965]

cant get to tank with stick as its in the floor

 

[rallyart]

My old boat would read empty at 1/2 tank. It would also list to port with a passenger in the boat. That worked out well as it would start to stutter when it actually got low and if you levelled the boat you had about 15 miles cruising left. Boat fuel gauges are sooooo much fun.

 

[Silvertip]

There very likely is no adjusting screw on the back of the gauge. Fuel gauges can however be calibrated for only ONE point on the gauge. Empty, full, or any point in-between. The logical point to calibrate is EMPTY since you know when the tank is full (because you filled it!!!) You need to calibrate the gauge when the boat is in the water as that's the attitude the boat will be in at rest. With the tank near empty (not bone dry), you bend the arm the float is mounted on to achieve the desired reading on the gauge. You must, of course make sure the float is not fuel-saturated which would make it sink. Fuel sloshes around after the tank gets about 2/3 or less so some bouncing of the gauge is normal and unavoidable.

 

[JoLin]

Depends mostly on the size/shape of the tank and location of the sender. My last boat (Four Winns 27') had a tall rectangular tank that sat sideways in the hull, and the sender was mounted in the center of the tank. The gauge was always accurate to within 1/8th of a tank.

My Carver has a long, shallow tank that sits fore-aft under the cabin sole, and the sender is all the way at the rear of the tank. At rest the gauge is semi-accurate, underway it's all over the place depending on how much the boat is pitching. On plane, the tank can be near empty but the gauge will read full because all the fuel runs to the rear of the tank, where the sending unit is.