Ok so I got the boat back from service and the engines are running fine and the work to get the electrical running is beginning. Guy I bought it from had told me the fuel and tach gauges do not work and this was obvious on our first outing. Second day out I looked down and the tachs were both working fine, third outing I noticed the tach needles were tracking up and down with the rpm's of the engines seemingly accurate but the needle positions were off- idle was reading at about 4-5 thousand rpm and on 1/2 throttle was reading over 7 thousand. Possibilties? Are the gauges ruined with rust or corrosion causing the changing position? Any help on where to start would be great.
