Gas Tank

[dwleo]

Hi Guys,
Haven't had much to query for a while but now I do.
I have a 2500 SCR that the manual says has a 75 US Gal gas tank. I live in Vancouver so everything is metric and 75 US Gal is eual to 284 L.
My gauge was reading less than 1/4 tank (needle bouncing from empty to just over 1/4) so I filled up. I should have room for close to 230 - 250 L but it only took 165 L.
So which is more likely:
1. The sender is faulty; or
2. The gauge is faulty

Appreciate any and all replies.
Thanks.

[mmwjr]

The sender is notorious for being inaccurate.

[viper12161]

I put a new sender in and I still have inaccuracy lol. I filled up the other day, it was full...yet still reading between 3/4 and full on the gauge.

[mmwjr]

Originally Posted by viper12161

I put a new sender in and I still have inaccuracy lol. I filled up the other day, it was full...yet still reading between 3/4 and full on the gauge.

What type of sender did you use, arm or reed?

Is the boat sitting level? There’s no baffles in a boat fuel tank so the gas sloshing throws off the reading. Sitting in the water at rest it should be fairly accurate.

[viper12161]

The type that has the float that goes up and down the center cylinder. Changed it about 3-4 years ago, so honestly don't recall the specific model. Boat was flat and not moving...well it is the Bay...so as calm as to be expected Turned key on after fueling....was reading between 3/4 and full. I have just given up and assume it is about a 1/4 tank off at this point and always fill after we get under half. I had an issue with one of the sending mount screws being stripped, so I am not taking it back out....is what it is and I just chalk it up as annoying

[mmwjr]

Understand. None of any boat I have owned has ever read that accurate either.

[dwleo]

OK. So the gauge and/or sender is unreliable.
How about the gallons/hour gauge. If that is accurate enough, it would greatly aid in how much gas you still have in the tank.

[mmwjr]

Originally Posted by dwleo

OK. So the gauge and/or sender is unreliable.
How about the gallons/hour gauge. If that is accurate enough, it would greatly aid in how much gas you still have in the tank.

The gallons/hour is not OEM so it would depend on who manufactured it.

[yahoo82]

Just a thought … The other issue that can happen a lot is problems with the fuel vent line. If there are any sags, or potential blockage, the fuel may be splashing back before the tank is actually topped off. Next time you fill up, once it’s “full” give it a moment to settle back and try filling slowly? My last boat was notorious for splashing back before it was full … not always but probably depended on the pump, temp, or maybe how the boat was sitting in the water.

[dwleo]

Manufactured by Floscan

[dwleo]

I'll try next time I fill up.
Thanks.

[Mr Hemi]

I dont like to run my 2500 SCR with a full tank, seems to be under powered a bit.
I have the 5.0 MPI.

My gauge is not really accurate either, but its better now with new gauge, so is my temperature gauge which always said i was running a bit hot around 175-180.
The best way to test the gauge would be to fill it all the way up and see where it sits on the gauge.
If it sits at full I would not worry about it.
Seems when you get down to the last 1/4 tank gauge really starts to bounce around?.
Curious what prop pitch you are running, still using a 3x3 configuration??? Grant.