A lot of Whalers came with tank mounted fuel gauges at the sender port, made by Rochester. Something like this? http://www.rochestergauges.com/pages/PDFs/49S.pdf
Would anyone know the depth of the tank and the fuel capacity of a 1980 171? I`am sure it is the original tank, the boat has only been in fresh water..I would replace the whole unit (sending and guage) if i knew what to replace it with.Any suggestions..Tks BoBo