77 fuel sending unit and gauge

[leggman]

I removed the fuel sender from my newly purchased 77 and it wasn't too bad but I put it into the ultrasonic evaporust and in about ten minutes it looks and works like new. I checked it with an OHM meter to confirm.
Question is I have less than one volt at the sender when the key is on and the gauge doesn't work at all.
I will be removing the tank for a good cleaning because it is nasty inside. Not a lot of rust but it looks like someone (maybe honda) tried a sealer and it is peeling off.

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[Sugs]

Boy, I think with that sealer in there I'd be looking at Ebay for another tank.

[Track T 2411]

I honestly don't think that's sealer, as there's no signs of it on the sides of the tank. Probably the final remnants of desiccated fuel sitting in the tank for years. I think you'll find that much of it will break loose with a good tossing of the tank with a cupfull of nuts and bolts inside. Then proceed with a de-rusting agent.

[Whiskerfish]

do you have a good 7 volt system?

[flyin900]

I think that maybe a sealer in there, as the side looks like it was partially done but not well. It looks like the Kreem brand of liner which are known to be not too fond of modern gas and break down eventually. There are specific chemicals to clean out old tank liners and with some help from the nuts and bolts you can end up with a good tank again. Although a new liner may still be needed.
If you can find a decent used tank for reasonable money then I would also go that route, since by the time you buy the chemicals and the work required you may be further ahead with a replacement tank.