373 fuel gauge

Jun 23, 2013
271
Beneteau 373 Newport
Anyone tried to get a "calibration" of the fuel gauge?
Due to the shape of the tank my gauge sits above the full mark until many gallons are used then rapidly starts moving toward empty. Have tried to use engine hours and an average consumption along with gallons to fill. This doesn't really work due to differing gph with rpms and not really knowing when tank is full (guessing with noise and diaper under vent to preclude fuel spill).
Gallons used or remaining when gauge moves off full?
When at 3/4 etc?

Thanks,
Bob
 

Rick I

.
Jan 6, 2007
414
CS36Merlin and Beneteau 393 - Toronto
My 393 gauge is the same. I've learnt to read it. Just takes time. Every sailboat I've had it's been like that. One trip down the Waterway where it's mostly motoring and you get to understand the gauge.
 

DougM

.
Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
Anyone tried to get a "calibration" of the fuel gauge?
Due to the shape of the tank my gauge sits above the full mark until many gallons are used then rapidly starts moving toward empty. Have tried to use engine hours and an average consumption along with gallons to fill. This doesn't really work due to differing gph with rpms and not really knowing when tank is full (guessing with noise and diaper under vent to preclude fuel spill).
Gallons used or remaining when gauge moves off full?
When at 3/4 etc?

Thanks,
Bob
Same issue with the tank in my 323. With its 17 gallon tank, the gauge needle doesn't come off the full peg until seven gallons are used. You really can't go by engine hours or clock hours because wind, current, and chop, as well as number of people aboard, all make a little difference. Over time, I have just filled up at different fuel gauge indicated levels and kept track of the number of gallons. From that, a little graph can be drawn showing the gallons at different points between full and empty. I have been a little timid about charting actual numbers below 1/4 tank though. (When the engine quits, the tank is probably empty).
If the tank wasn't so hard to access, a sight glass or even a dipstick would be a good alternative.
 
Aug 27, 2014
91
Beneteau 373 San Diego
Bob, Thanks for this topic. Our 373 has been pinned at full the whole season, since the first of May, and while we can't take our boat out every weekend, I was finding it hard to believe that we had used no fuel at all this year. Certainly is a bit of a problem since before haul out it is recommended that we have our tank at about 7/8. Once the needle moves I will make a note of how many gallons to fill the tank and re-post my findings. Maybe we can get an idea of how the gauge works from pooling all of our 373 fuel data together.
 
Jan 22, 2008
169
Beneteau 343 Saint Helens, Oregon OR
If the guage and sender are similar to my 343, it all depends on who installed and how much they trimmed off the swing arm on the float. Pull the float and measure. While you have it out you can put a ruler next to it and measure depth vs reading. Still won't give you actual fuel unless your tank is somewhat rectangular. 343 tank tapers from 10" deep down to about 3-1/2.
 
Jun 23, 2013
271
Beneteau 373 Newport
373 tank not only tapers but the smallest section is up higher due to the position aft under the berth. The gauge sender is in the fwd, deeper part of the tank. Therefore the sender does not see a change in fuel depth until the higher section is used.
 
May 9, 2006
56
Beneteau 373 Mystic, CT
Fuel gauge sender calibration.

Bob:

The sender is by VDO and I have attached their guide to calibration. Beneteau clearly did not bother to calibrate on installation. This will improve the operation significantly. I have also attached a chart I prepared after calibration, to better gauge fuel remaining. Hope these help.



Anyone tried to get a "calibration" of the fuel gauge?
Due to the shape of the tank my gauge sits above the full mark until many gallons are used then rapidly starts moving toward empty. Have tried to use engine hours and an average consumption along with gallons to fill. This doesn't really work due to differing gph with rpms and not really knowing when tank is full (guessing with noise and diaper under vent to preclude fuel spill).
Gallons used or remaining when gauge moves off full?
When at 3/4 etc?

Thanks,
Bob
 

Attachments

Jun 23, 2013
271
Beneteau 373 Newport
Bob,
Thanks for the info!
Currently my gauge, which is a VDO showing only marks at 4/4 and 1/4, does not move off full until the tank is ~ half empty.
I now show full and I have 23 hours since last fill. Use a diaper at the vent and fill until I hear gurgling in the vent.
My engine is the 3GM30 so different fuel consumption. But I assume we have the same tank under the aft berth port.
When I have a lay day with the tank low I will pull the sender and measure the arms per your info. ( currently in SC heading south)
Thanks again,
Bob
PS close friend lives near you, member at Ram Island YC.