I have a 2002 Mercury 50 ELPTO. It starts and runs on a hose perfectly. On the the water, it starts a little harder (but starts) warms up nicely and idles well at first. It will then get the boat up quickly and run great up to 5500 all day long. Problem is that after the first run, when I come back down to idle, it will start to miss and sputter at low RPMs for the rest of the day. It will still get up and go like a champ all day. Also, when I get back home after being on the water, it won't idle on the hose. The next morning, it will idle perfectly on the hose again. So far this year, the compression has been checked and is good, the carbs have been taken apart and cleaned, but not overhauled as the mechanic said they looked good, and the fuel lines have been replaced and the system is full of good fuel. Help!
