84 H31 Checking Fuel Tank Question

Mar 28, 2014
51
Hunter 31 Lake Norman, NC
What advice can I get for determining the amount of fuel that is in the fuel tank?
 
May 24, 2004
7,176
CC 30 South Florida
Determine the size of your tank in gallons then top it off and the amount of fuel will be approximately equal to the size in gallons. I'm not trying to be funny, this is the most practical way I can think of for getting your answer. With the tank full now, if you add an hour meter connected to the key switch it will record the number of hours the engine is run and next time you top the tank up you can get from the reading at the pump the number of gallons the engine burned during those hours. By dividing the number of gallons by the hours you can get the engine's "average burn rate". You may also need to create a log indicating the hour meter reading every time you top off. At any point after you can determine how many hours the engine has ran since last fill up and by applying the average burn rate you may tell how many gallons you have used and how many should be left in the tank. You may go through the process of calculating the average burn rate a few times just to narrow down the figures for the average. This method is more exact than a fuel gauge and provides you the information to be able to calculate your range according to the prevalent conditions when in the water. Don't forget to allow for a safety margin or reserve of around 15% of the tank size. Not all the fuel in the tank is usable, the engine will start sucking air way before the tank is empty. It can happen quicker in foul weather conditions will fuel sloshing around in the tank.
 
Jan 22, 2008
1,667
Hunter 34 Alameda CA
Good advice above.

When I was ready to refill my plastic tank (same as yours I believe), I would shine a light through it and mark the outside at that level with a magic marker then after filling it would know the gallons taken on. I wrote that number down on the tank as well. Then it was easy to determine the burn rate from how long I ran the engine (no hour meter either, just a logbook) and subsequent full tank range or time. That is until I ran out of fuel. As most of the Hunter 34 owners know, the 25 gallon tank per the label only holds 21 gallons. Perhaps someone with the 31 model can tell us what their actual capacity versus spec'd is. With no fuel gauges, the volume had to be determined empirically. I just keep very close tabs on my operation time. I top off via Jerry can about 5 gallons for every 8 hours run.
 

kito

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Sep 13, 2012
2,011
1979 Hunter Cherubini 30 Clemmons
Great advice. Will do. I appreciate your response.
Hey Choover. Did you buy your Hunter 31 recently on Lake Norman? Just wondering if it's the same one I looked at. It was a 84 Hunter 31 at Holiday Marina.
 

pateco

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Aug 12, 2014
2,207
Hunter 31 (1983) Pompano Beach FL
If you find out how many gallons it actually holds please repost here. I am also the new owner of a 1983 Hunter 31. You can check out our restoration project at The Stargazer Adventure
 
Mar 28, 2014
51
Hunter 31 Lake Norman, NC
kito . . . i bought the h31 on Lake Norman but it was not at Holiday.
 

HMT2

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Mar 20, 2014
900
Hunter 31 828 Shoreacres, TX
Fill the tank, get a clean dowel stick it in the opening on your tank mark where the fuel mark stops. That is full...voila, a fuel gauge! Keep it handy. If you need actual gallons do what was suggested above. Also you can check out sailboatdata.com. Here is a link to yours and mine http://sailboatdata.com/viewrecord.asp?class_id=1763. If your tanks are original this is right on mine.
 
Dec 27, 2013
3
Hunter 31 Guntersville
What advice can I get for determining the amount of fuel that is in the fuel tank?
I bought a Hunter 31 about a year ago. The plastic fuel tank has fuel levels in gallons marked on the tank. The plastic is so discolored that one can not tell the level of diesel in the tank. Any suggestions on determining the amount of fuel in the tank?
 

mr c

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Aug 4, 2010
77
hunter sailboat 31 northport
I put a flashlight against the tank. You can see the fuel sloshing about.
 

pateco

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Aug 12, 2014
2,207
Hunter 31 (1983) Pompano Beach FL
The PO of the Stargazer added a Fuel gauge, but I ran out when the gauge still read 1/4 full. I have not spent the time figuring out how to adjust the gauge, and now consider 1/4 to be Empty.