So I wanted to post my story in hopes that it could help others with the same issues. In early last March I bought a 16' 1983 Malibu with a 40hp 2 stroke 2 cylinder Mariner. Other than an issue with having to locate my prop at the bottom of Lake Monroe, luckily near the boat ramp, on it's maiden voyage it ran great! I then wanted to replace the plugs but had no info and the plugs in the motor were two different types, no help there. So I found the right ones, with help from this forum in locating the serial numbers since I couldn't read the info plate on the motor bracket. The boat then began to have issues bogging down at high speeds/Rpms. So after many discussions with my friend we believed it to be fuel related. So the journey began....I replaced everything including the tank all the way to the fuel pump, but still same issue. Next was the fuel pump, so I then replaced the pump with the gasket between the motor and pump but still nothing...so then I went in to look at the carbs which means removing the starter and noticed that the gasket between the fuel pump and motor wasn't installed correctly so I fixed it and since the starter was out I replaced the fuel line from the pump to the carbs with lines from an auto store. Took the boat out and still had same problem. Then I noticed that the tee, that split the fuel line in two to connect to each carb, was weighing down the bottom line going to the bottom carb and pinching the line shut....I then bought thicker o.d. Fuel line and now the boat runs like a champ!!In the begining it was air at connections and it was a bad fuel pump but along the way I created more problems that gave the exact same symptoms making me think that maybe it wasn't a fuel issue. Hope this somehow helps.
