Went out on a long cruise offshore for snapper, dorado, and whoos. Gauge said I burned around 67 gal when my main tank went dry...92 gallons. So my question is, that's way off, almost 32 gal off, so its the gauge faulty, is there any way to calibrate it? I was easy on the throttle, knowing that my conversation with my Yamaha tech a few weeks ago said at max throttle the 250 ox66 burns 29 gal an hr. Either that or the tank, which is 92 gallons is really not 92 gals, even though I know it is. When we talk about how much tanks really holds what are we talking about is it more like 80 gals with baffles etc. Its the original tank. Just trying to think through this a bit more. I topped off the tank so I know it was full before I left, but cant recall ever filling it from bone dry to see what its true capacity really is, my sender stopped working a while back so I don't have that to true the numbers up.
Yamaha Fuel Managment - how accurate
- Thread starter The_Chain
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On our 92 Explorer we had two tanks a 92 gallon and a 48? gallon. On many occasions we would run the 92 gallon tank dry and then switch to the auxiliary tank. According to our Flo-Scan gauge we would get between 87 and 90 gallons out of the 92 gallon tank. After running the tank dry at least ten times, I started to coincidentally have problems blowing fuel pumps. A Yamaha mechanic told me if you starve the fuel pumps they tend to rupture, we intentionally stopped running the tank all the way down and the problem went away. By the way this was with a 2000 Yamaha 250EFI.
If memory serves me correctly, our 250EFI also burned 29gph at full throttle and roughly 14gph at 25knots. Tuna trolling was horrible, roughly 7gph at 7 knots (we do much better trolling with the marlin running twins).
I suspect your fuel management is not accurate or perhaps you just need to change the dip switch settings. I have been on abut a dozen boats with three different brands of fuel management gauges, all of them were within 5 percent of actual usage.
If memory serves me correctly, our 250EFI also burned 29gph at full throttle and roughly 14gph at 25knots. Tuna trolling was horrible, roughly 7gph at 7 knots (we do much better trolling with the marlin running twins).
I suspect your fuel management is not accurate or perhaps you just need to change the dip switch settings. I have been on abut a dozen boats with three different brands of fuel management gauges, all of them were within 5 percent of actual usage.
Doc Stressor
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While you can adjust the calibration of the fuel management system with the DIP switches at the back of the gage, but if I recall correctly, you can't correct more than 4%.
Fill your tank…when your fuel management gauge says you burned say,50 gallons, top it off again. See how many gallons it actually takes. At that point you will have a better idea of whats really going on and can figure out what you want to do from there (i.e repair/ replace / adjust the gauge.)
bayrat said:
This is a good start...thanks bayrat and others...guess Monday morning I didn't have much brain power and let you guys all do some thinking for me.. :hmm
Yamaha Fuel Management on our Islander with twin F150s is consistently within 0.7% (0.007) of the actual fuel when filling the tank.
I would check that the fuel flow sensor for the fuel management is mounted properly, as there is an "up" direction for flow.
You can also pull the sensors and blow through them to be sure they are clean and spinning freely.
My bet is the orientation.
Brian
I would check that the fuel flow sensor for the fuel management is mounted properly, as there is an "up" direction for flow.
You can also pull the sensors and blow through them to be sure they are clean and spinning freely.
My bet is the orientation.
Brian
Doc Stressor
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My fuel managment system is accurate within a few percent when I fill up the boat on the trailer at a road side gas station. But when I fill up at my marina with the boat in the water, the tank always takes at least 10% more than what the gauges says that I used. The marina says that's because the tank is level in the water while the tank is at an angle when on the trailer. Well, maybe. :roll:
ROBERTH
GreatGrady Captain
Mine has nearly always been right on the money! We burned 104.5 gallons last weekend and I tried to round it off and paid for 105 gallons and it was all we could do to sqeeze that 1/2 gallon between both tanks.
I run our 52 gal. aux. down to near 48 to 50 gallons and keep mental note of that, then switch over to 152 gal. tank and run rest of the day.
When we get to refuel, we do our mix ratio's for Startron and Ring Free based upon what we burned in aux. tank, then as we fill, it is done at the same gallon it said it burned. Then we finish the Main tank with the remaining gallons and mixes.
One time it was off, but that was a day when I noticed on the Yamaha gauges, they were off on the speed. I cleared the pitot tube and seems all was good again. Not sure how that affected the burn, but seems that the gauges were confused on that day. Not had the issue since.
I run our 52 gal. aux. down to near 48 to 50 gallons and keep mental note of that, then switch over to 152 gal. tank and run rest of the day.
When we get to refuel, we do our mix ratio's for Startron and Ring Free based upon what we burned in aux. tank, then as we fill, it is done at the same gallon it said it burned. Then we finish the Main tank with the remaining gallons and mixes.
One time it was off, but that was a day when I noticed on the Yamaha gauges, they were off on the speed. I cleared the pitot tube and seems all was good again. Not sure how that affected the burn, but seems that the gauges were confused on that day. Not had the issue since.
I have to agree that mine is right on the money too. Last weekend started with a full tank and burned 53 gallons. Went to fill up and only could squeeze 53 back in. Might have been a 1/2 gallon difference but I remembered it because I was shocked.