Calibrating fuel level

[dsherburn]

On one of the Ranger Tug webinars this spring, someone had mentioned a fuel tank calibration method by where the tank doesnt have to be dry...it is done by pulling the sensor out of the tank. I believe the procedure was documented in a pdf. Does anyone know where this might be? I have a Ranger Tug 23 with the Yamaha 200.

 

[BB marine]

Dan ,I did calibrations using the sending unit.
viewtopic.php?f=18&t=10780&start=0&hilit=calibrations

I found the accuracy of the sending unit after calibrations to be within 3 or less accurate after the first 10 gallons from full similar to how a car fuel gauge works. Before doing this the factory calibration was 20+ gallons off.

PM me if you have any questions. I use the Garmin fuel calibrations too. With the sender calibrated it is usually within a 2 or 3 gallons of the Garmin.

The Volvo may have different steps for calibrating compared to the Yamaha but I think the method I used can be altered to achieve the same results with the Yamaha.

 

[dsherburn]

Thanks Brian- I've sent a PM
ds

 

[Navigator's Son]

Has anyone found they have the reverse guage issue?

Using the Garmin fuel flow - I setup for an 80 gallon tank. I top off the tank - literally fuel sitting in the hose visible with cap off. I set "fill all tanks".

Now my Garmin reports I have 80 gallons of fuel. I run around for hours, Chartplotter is reading average of 2 mpg with a burn rate of 5.4 gph. Per the Garmin calculations, I have used up 50 gallons of fuel, and I only have 30 gallons in the tank, right?

No matter what I do at the pump, I'm lucky to get 35 gallons of fuel back into the tank.

I run my boat at 2550 RPM's averaging 11 - 12 knots. Am I just really getting better than 2 mpg and much lower than 5.4 gph burn?

 

[dsherburn]

I've found I'm burning less fuel that the Garmin shows (I use a similar procedure...fill the tank- tell the Garmin it's full). My Yamaha does allow you to tweak the fuel flow calibration a bit, but I'm at the max allowable "tweak" setting so it's pretty close but not "dead on". For some reason the Yamaha flow measurement is showing more flow (and so Garmin) than I experience at fill up.

 

[Rocky Lou]

My Yamaha 6YC reads at least 30 gallons less than Garmin. I trust that the Garmin is fairly accurate...I reset with each fill up and the burn rate seems close to what I expect for a reading. I understand you can recalibrate, without an empty tank, the sensors if you want to remove them. I'll probably have a Yamaha tech recalibrate at annual service unless I get convinced it's really a simple process. Tweaking the 6YC has a maximum of +/-7% which would still leave me way off.

I'm very surprised my Yamaha calibration is off since it was done by one of the few certified Master Techs. in the US. Unfortunately, he's a long way from me now.

 

[BB marine]

I have found the Garmin to be a minimum of 5% off many and times 10% off. That is not really an issue as long as you are not running the fuel level to a minimum. There are a few trips that I have taken that require running to low fuel levels. When I did the Mississippi River run 250 miles with 80 gallon capacity. I wanted more than one way of gauging how much fuel I have in reserve. For this reason I did the sending unit calibrations. If the calibrations are done as I described in this link viewtopic.php?f=18&t=10780&start=0&hilit=calibrations I find the accuracy better than the Garmin. I have a auxiliary 22 gallon tank that I installed. It is only filled by a transfer pump from the main tank. I must keep a log when I transfer. When I last transferred fuel I didn't log the transfer. All I had to go by as for fuel in my main tank was my fuel tank sending unit. The Garmin was not reset ( my mistake) when I transferred fuel. My fuel tank sending unit was sending a value to the EVC dash gauge 41 gallons left. The Garmin was showing 26 gallons left. I filled the tank and I pumped 38.6 gallons of fuel in the tank. The sending unit was off by .4 gallons. The boat must be at a level attitude and first 10 gallons used from a full tank the accuracy is reliable. I still use the Garmin and rely on it. I trust the fuel gauge more than I do the Garmin.

 

[Rocky Lou]

Thanks for posting the calibration instructions. I will review those carefully and make a determination if it's within my tech 'range'.

I agree that two gauges are essential even though I never plan to run lower that 1/4 remaining fuel. I have two 150g tanks, but, there is no reserve that I am aware of. Hence, if I run out, I'm drifting. On other boats, I've had a reserve with a valve switch.

As you stated, the Garmin is fine if you remember to reset each fill up, but, everyone forgets once in a while. Having a 'real time' read is preferable and I'm happy to hear more accurate.