Hello everyone. I am having an issue with a Mercury outboard that came with a boat I purchased last month. The gentleman I purchased it from told me he had the carb and lower unit rebuilt to the tune of $600. He also tank ran it for me and it idled decent. The first time I took it out on the water, it failed to idle even with the engine warm/hot. Also, when trying to go wot it stutters/stumbles/skips to the point I need to back off. Otherwise it runs great in the midrange. I have searched everywhere for how to tune this carb in order to get the engine to idle and run wot to no avail. I replaced the plugs in addition to running a fuel cleaner/treatment (Berryman's) with 93 octane fuel/Pennzoil XLF oil. Is there a trick to get this engine to idle and not stutter during wot running? It is a 1988 Mercury 20HP 2-stroke. I am running a Solas Amita 3 13 pitch prop. Any help with this issue would be tremendous!