Fuel Tank Dial

May 26, 2015
2
Hunter 29.5 Mattapoisett
Recently purchased 1995 Hunter 29.5 ran out of fuel even though the fuel level indicator registered more that 1/2 full. Lucky we were moored. How extensive a project is investigating what the cause was/is?
 
Dec 14, 2003
1,434
Hunter 34 Lake of Two Mountains, QC, Can
Cause is either the gauge or the sender. More than likely the sender. Plenty of info on how to test on Google. Most of us don't rely on fuel gauge but rather calculate usage with hour meter. If you have one, fill the tank and take a reading of the hour meter. Your engine (2GM20F ?) probably burns less than 1/2 gallon per hour. Don't trust whatever your manual says about fuel tank capacity. It's likely about 90% of that and you cannot pump the bottom of the tank as the pick up tube doesn't reach that low.
So figure on about 80% of posted capacity available. Run 10 or 15 hours and fill up again, this time noting how many gallons you add and the hour meter. A simple math # gallons / hours run will tell you your burn rate and you should be good never to run out of fuel again. Good luck
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
Recently purchased 1995 Hunter 29.5 ran out of fuel even though the fuel level indicator registered more that 1/2 full. Lucky we were moored. How extensive a project is investigating what the cause was/is?
Its usually a matter of removing the wire coming from the sender on the rear of the gauge, and then see what the gauge reads... then very briefly apply a ground to the post you just removed the sender wire from.... when you apply a ground, it should cause the gauge needle to go the other way than it is when no ground is attached. If it does, this indicates the gauge as working proper... so the sender will be the likely cause of the failure.

So remove the sender from the tank and see if its stuck or if its improperly adjusted.

With the gauge removed from the tank, the wire hooked up and the mounting flange grounded, you should be able to get full range on the gauge by moving the arm... but the arm length will determine the "throw" needed for the depth of the tank to get an accurate reading of the fuel level.

If the gauge test shows the gauge to be working, but the sender does not make any indication, you will need to check continuity in the sender wire and in the tank ground wire before assuming the sender is bad.

The system is really simple... the sender is actually a potentiometer in the ground side of the circuit, and the gauge just measures the ohm differences as the potentiometer moves up and down the scale. The system is powered by the hot wire connected to the gauge.
 
Jun 2, 2004
241
Hunter 410 Charlevoix, MI
Are you sure the tank was empty?? My 1995 29.5 had a nasty habit - it ran out of fuel with fuel in the tank! I finally figured out that there was a screen soldered on the end of the pickup tube which was getting plugged with small plastic shavings from when the manufacturer drilled the tank holes. I removed the screen and all was well :)