I have a 2000 42 Lighting, switched it to E85 and filled the tanks. Now the gauges are all stuck on full???
Any help on this?
I tried to pull one off the senders and couldn't get it out because of the length of it. It looked like a 5/16 aluminum tube?

corrosion from fuel can be the problem

If the sender is the non moving parts type (capacitance) you will need to re-calibrate it. reset empty then re-set full. If you can get it out there will be an outer aluminum tube and a smaller tube inside of the larger one. The older type you need to adjust for empty the newer ones self calibrate for empty. Good luck.

Here is a link to the programming instructions, it does say up to 10% alcohol. May call them and ask about E85.

sender_calibration_current_2015.pdf (harmonracingcells.com)

I don't want to take away from the original question, but I'd be curious to know why and what was 'switched' to E85. Ethanol is a horrific fuel substance, especially for a boat engine that's 20 years old... it was only ever to get votes in corn states. Nothing about it is 'good' for anyone from the environment to the wallet.

Now you're using 85% Ethanol, which loves to attract moisture, sitting inside a vented fuel system, literally sitting on top of nothing but water..?

Unless you've redesigned the engine and supporting components to specifically run on E85, you're looking at a significant power loss, thus fuel economy loss as well...

Every gallon of E85 contains 30% less energy than gasoline.

Was this intentional or accidental filling?