No Fuel Sending Unit

[MPKehoe09]

Sorry for the duplicate...Figured this is the better spot for my post.
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I recently purchased a 1998 175 Osprey. The previous owner mentioned that the existing fuel gauge didn't work, so I figured I just needed a new sending unit, and problem solved.

After closer inspection, I'm a bit confused...It looks like the sending unit was removed, and some sort of "cap" with a clear lens was installed (epoxied??) in place. Right near this cap, are three wires that were cut (Black, Green, and Pink). Green is my ground that traces back to the fuel filler inlet. The black grounds to the battery, and the pink traced back to my fuel gauge.

This leads me to believe at one point there was a sending unit, and something was retrofitted. Any idea why this would be done?

I've been using a portable above deck tank, but would love to get the internal tank in use.
However, the lack of the sending unit and retro-fitted cap concerns me.

Anyone have any ideas?

[Capt. Bob]

I'll guess.

The original sending unit mounting screws rusted and couldn't be removed or stripped and drilled out, head broke off. All of this occurred when the PO/mechanic tried to replace the sending unit. What you have now was "glued" in place since he couldn't attach the new sender with the screws.

You are running on the above deck tank because?

[MPKehoe09]

Simply running the above deck tank because I was skeptical to using the internal tank with the "glued" cap. Plus I'll never really be able to determine the amount of fuel in the tank without a sending unit, or being able to stick a dipstick in there.

Also, how would i properly ground the green "grounding wire" that runs up to the clamps at the fuel filler valve? At one point i assumed it grounded to the sending unit. Part of me says not to worry about, but research i've done suggests making sure the ground is entact due to static electricity concerns. Can i just bring this to any other ground or the (-) battery terminal?

[Capt. Bob]

If you wish to do it properly, you would bond the fuel fill and the tank to each other and both to ground. I used a negative battery terminal for this purpose. Many aluminum tanks have a dedicated bonding tap for this purpose.

You may wish to remove the fuel present and start with a fresh amount. Just a thought.

Good luck.

[MPKehoe09]

Thanks for the input, Capt. Bob.

Since my tank is poly, and the sending unit has been removed, how would you suggest I ground the fuel filler to the tank itself?
In the picture I originally attached, there is a metal shut-off valve at the fuel pick up for the outboard.
Should I bond the ground wire from the fuel filler to this ball valve? And then run to my (-) terminal?

Lastly, if I wish to somehow reinstall a fuel sending unit, pardon my ignorance, but am I out of my mind in suggesting the following?

- Use a dremel or router, with a bit depth not to penetrate the thickness of the tank.
- Score/Cut circle around the perimeter of the "glued cap".
- Vacuum out the debris/particles.
- Use utility knife to cut remaining thickness to prevent particles from falling into tank.
- On a new piece of oversized poly, cut the proper size hole for a new fuel sending unit.
- Place the oversized piece of polly over the existing hole and use a product such as "TAP Poly-Weld" to bond the new piece of material to the old tank.
- Cut fuel sender length to account for the added material thickness.
- Install new fuel send, and ground with wire to filler inlet?

Crazy (dumb) idea or plausible?

[Capt. Bob]

Some ideas.

http://classicaquasport.com/smf/index.php?topic=9912.0

http://classicaquasport.com/smf/index.php?topic=10577.0

http://classicaquasport.com/smf/index.php?topic=9383.0

Lastly.

http://classicaquasport.com/smf/index.php?topic=10611.0

Good luck.

[MPKehoe09]

Thanks, those are some helpful threads.

For my tank, since my cap is glued/epoxied in place, would you recommend cutting a new hole for the sending unit?
Or somehow trying to remove the existing cap?

Thanks,

[Capt. Bob]

I would try and remove the existing "cap" and see the condition of the tank at that point. You can always repair the existing and cut a new hole.

Does your model have an access hatch or just the deck plates for access?

[MPKehoe09]

As far as access to the tank, just the deck plates.

Since i'm working in a gas vapor sensitive area, any suggestions on something to use to break up the glue/epoxy?

Thanks again...