I have a 2000 MERCURY 200EFI. I had a new powerhead put in last summer and it's been a piece of junk ever since. The mechanic over oiled the fuel tanks for the brake-in period and plugs would foul every 5 min of run time. After finally getting past the break-in period the engine would run great...
I have a 2000 Mercury 200EFI that idles terrible. It shakes really bad at idle speed and dies when I put it in neutral. It runs great at fullthrottle. I just put 6 new sparkplugs in hoping that was the problem, but I guessed wrong. Any suggestions what may be wrong would be appreciated. THANKS