CONTINUOUSWAVE

When I purchased my 1991 Montauk in 2015, I replaced the poor condition Atwood 6-gallon tank with a 22 gallon Moeller white tank that fits perfectly under the RPS. The cap that came with the tank has a built in fuel gauge. There is a float on a curled wire coming down from the cap, that only travels half way down the tank. So when it reads empty, I really still have 11 gallons. This works for a quick assessment of whether my tank is full, 3/4 or 1/2, but does not provide any benefit for knowing 1/3, 1/4, etc.

Is there a simple replacement available for the cap that would give accurate fuel measurement for this tank?

Or, is there a way to extend the tank level gauge so it reads the lower half of the tank?

I would be okay with it reading full, even when the tank is 3/4-FULL or 1/2-FULL, but I would prefer to know my tank level when it gets lower.

Or, Is there a way to install a simple fuel gauge that is not part of the cap, that could be read either on top of the tank or with a connection to a gauge by the console?

I appreciate your help. I have learned a lot about my boat from this forum.

Andrew

I also have the white 22-gallon Moeller fuel tank. When this tank first came out they had problems with the fuel gauge cap. Moeller was not much help, but a replacement gauge cap is manufactured by Kelch. The replacement gauge is a vented 2-1/4-inch threaded cap with a 12-1/4-inch float depth Kelch part number #7J203085. You can order the gauge with different float depths.

It may be possible to fit a remote sender or sensor to sense the fuel tank level and send an electrical signal to a remote electrical gauge or even a NMEA-2000 network. I anticipate a sender could be installed by simply finding an appropriate surface on the top of the Moeller 22-gallon fuel tank, cutting the necessary hole for the sender and the sender's mounting fasteners, and installing the sender on the tank. Senders are installed all the time in below deck fuel tanks, so I do not see a particular obstacle to installing a sender in an on-deck fuel tank.

I don't know if the non-conductive nature of the tank is an impediment. I have seen below-deck fuel tanks made from non-conductive material and have an electrical sender. On that basis I would infer that the non-conductive nature of the tank is not a problem.

Making a modification to the Moeller 22-gallon fuel tank as I describe would be something you could undertake yourself, I suspect. The electrical wiring should probably include a connector so the tank remains portable and could be removed from the boat.

Were I to undertake a project like this, I would probably use a sender other than the mechanical float arm and rheostat type sender. For some guidance on tank level senders see these prior discussions and articles:

Fuel Tank Level Sender: Electrical
http://continuouswave.com/ubb/Forum6/HTML/000632.html

NMEA-2000 Instrumentation: Fluid Tank Level Monitoring
http://continuouswave.com/whaler/reference/fluidTankLevelNMEA2000.html