Question? Northstar F210 Readings

[tuna taxi]

I have not calibrated the fuel flow reading my F210 and was wondering........

While heading out Sunday morning I noticed that the reading on the meter were pretty erratic (see pictures) 4000rpm = 10 gph, 3900 rpm=7gph.......can 1000 rpm really make that much of a difference? I believe that the factory setting are set to read fuel flow average every 10 seconds, I'll adjust it to 15 and see what it does. Anyone else have the same issue before calibrating the meter?

Another thing that I noticed was that the gph was much better whenever there was very little chop in the water, managed to see it go as low as 5gph at 3700rpm. Is that right?

[slief]

You asked if 1000 RPM could make that much of a difference in fuel flow and yes it can. I do think you meant 100 though based on your post. 100 RPM should not make that much of a diffence in GPH. The numbers you see are based on the moment or an average during a short period of time. If the computer polls the sensor every 15 seconds, you will get a less accurate realtime picture than if it were polling every ten seconds.

As to your questions about the chop.. Water conditions can have a huge impact on fuel usage.. Think of it this way, your car gets better milage on a smooth road at a given speed that it would traveling down a wash board road with whoopty doos.. Not only will there be more resistance for the boat to deal with, the props don't run as efficiently through the water as there is more turbulance from the chop..

One thing you might not have realized yet is the impact proper trim can have on fuel efficiency... Trim can play a huge role in squeezing the most out of your fuel tank regardless of the water conditions!