50 hp 4 stroke (1996)

Was out on Sunday and noticed what seemed like a misfire at low rpm. Seemed to be less at wot. Opened up the cowling after about an hour of running and smelled gasoline. On the top carb there was a line going nowhere. I’ve never noticed this before. Just an FYI, new E3 plugs less than 50 hours ago, use non-ethanol gas always and go out almost every weekend. The miss was gone after the second part of being out. Anyone know if the line is a breather or vent and if not, where should it go? Why would the miss just quit and start running good again? Thanks

Wow, no one?

Ok…new question….I’ve replaced my 50 hp with a brand new 2021 90 hp 4 stroke (Mercury) …yahoo! Well I’ve been switching everything over and the Mercury dealer that I bought it from said I can add all the analog gauges, including oil and water temp. They said all the sending units/sensors are pre-installed. I had to purchase a gauge harness for the gauges to hook up to the new 14 pin key harness. I’ve added all gauges, tach, volts, trim, oil pressure and water temperature…well the results, they all work fine EXCEPT the water and oil! I’ve put a call into the dealer but haven’t heard back. Anyone out there have any suggestions/answers? I had the same issue with the 50 hp but had to add the external heat sensor for the temp., but never was able to add the oil pressure gauge! Please help…