Boating How-To’s - Fuel Level Sender

Ok, so I posted a while ago about trying to see what is going on with my fuel sending unit. Well it is bad and now I need to change it out. So I tried yesterday and the way it is under the deck half of it is accessible and the other is not. I tried an off set screwdriver and still couldnt get 2 of the screws. does anyone have any suggestions? Maybe even a way to get a fuel reading without the sender? I know I have seen fuel flow sensors that would help gauge on how much gas I am using. ;?

I forgot to mention what kind of boat it is! it's a Wellcraft 23 w/a cuddy

You may need to instal a deck plate over the sending unit. Once it is done you will always have access to the sender. I have a 22 ProLine Walk around and it has a deck access plate over the sender. It is really convenient.

You may be able to remove the screws by spraying the with PB Blaster, let them set for 48 hours, and then clamp on a mini Vice Grip. However, if the deck covers half the top of the sender, you may not be able to pull it out even if you remove the screws. But, it's worth a try. Fuel usage sensors, such as those made by FloScan, are much more reliable and accurate. But, they are expensive and you need to know the capacity of your tank (and fill to capacity each fill up) to be able to know exactly how much fuel you have in the tank at any given moment.

You may be able to remove the screws by spraying the with PB Blaster, let them set for 48 hours, and then clamp on a mini Vice Grip. However, if the deck covers half the top of the sender, you may not be able to pull it out even if you remove the screws. But, it's worth a try. Fuel usage sensors, such as those made by FloScan, are much more reliable and accurate. But, they are expensive and you need to know the capacity of your tank (and fill to capacity each fill up) to be able to know exactly how much fuel you have in the tank at any given moment.

on my fuel flow meter, there is series of steps to set the amount of fuel.
so lets say I don't know how much fuel I have in the tank starting out, and add 50 gallons of fuel. I can set my fuel meter to read 50 gallons. I then proceed to burn 25 gallons. My meter states I have 25 gallons left. When I get more fuel and add 20 gallons I can re-set the starting gas amount to 45 gallons. The original amount of gas is unknown and is a cushion. I don't have to run the tank dry and I don't have to re-fill to the brim. I do need to know how to add the numbers of gallons I have and the number of gallons I am putting in so I can re-set the machine's starting fuel amount.

I don't think I paid 150 for the navman....very nice and easy to install.

If and when you DO get that sender off, I'd replace it with a stainless steel one. Look up WEMA boat fuel level sending unit. These are great.

Mine are maybe an inch or more short so when I read empty I still have a little cushion.

good luck

so the fuel flow meter can be used without removing my current fuel sender right? if so where does it,mount and what,are some recommended ones?

so the fuel flow meter can be used without removing my current fuel sender right? if so where does it,mount and what,are some recommended ones?

Yes you do not remove the fuel sender.

It mounts inline of the fuel hose before the engine, but AFTER the fuel filter.

I have my sender mounted on the inside transom, under my transom cover. It is a very simple device really, A precise propeller spins in a tube and the rate of the spin correlates to a GPH at the unit's matching dash gauge.

I have a Navman Fuel 2100, and was pretty cheap, somewhere around $115.00

Floscan is another name that comes to mind.

also the newer engines have them already built in and their gauges displays the GPH.

I think the Lowrance HDS series has an optional gizmo that does the same thing, that when hooked up to the HDS also gives MPG automatically.

so rather than using your GPS, noting the Speed on Ground, eyeballing the fuel flow meter and doing the math in your head, this does it constantly on the fly.

Ok, so I posted a while ago about trying to see what is going on with my fuel sending unit. Well it is bad and now I need to change it out. So I tried yesterday and the way it is under the deck half of it is accessible and the other is not. I tried an off set screwdriver and still couldnt get 2 of the screws. does anyone have any suggestions? Maybe even a way to get a fuel reading without the sender? I know I have seen fuel flow sensors that would help gauge on how much gas I am using. ;?

Typically when we can't get to the FSU we first try to remove the ring associated with the access plate. IF that doesn't work we will opt to cut in a larger access plate. THEN we will simply cut in a new FSU in a more accessible location and abandon the old unit. BUT every attempt will be exhausted before we abandon a FSU.

Typically when we can't get to the FSU we first try to remove the ring associated with the access plate. IF that doesn't work we will opt to cut in a larger access plate. THEN we will simply cut in a new FSU in a more accessible location and abandon the old unit. BUT every attempt will be exhausted before we abandon a FSU.

Yikes how do you cut a new hole with all those gas vapors?

A full tank has no vapors. Really the key is to be cautious, avoid open flames, sparks and be well ventilated.

I think I am going to cut a bigger hole and make a new access hatch. This one just seems too small to access anything that would have to be done in that area. I am also going to get a flow meter they just seem like it is a good thing to have. Thank you everyone for their advice!

What year is your boat. Seabob should be able to help you with this. Depending on what year it was built he may have had a hand in building your boat.