216 Bay Reef
New member
I have a 2001 Mercury 200xl carbureted engine on a boat i recently purchased. About to take it out for the first time and when starting, it's hard to start and needs to be choked for 30-60 seconds to keep from stalling. Pulled the plugs and noticed the top 2 plugs on both banks looked basically brand new still (just replaced all a couple months ago) while the other 4 have coloration from being fired. Did a compression test and have between 116-111 psi on all 6 cylinders. Engine idles around 800 rpm after warmed up, but shakes still. Started unplugging plug wires at idle and the top 2 are sparking, but not like the other 4. If I pull the bottom 4 wires while running, the engine stumbles more and it shocks the hell out of me, while the top 2 don't shock me and no change in idle. Could this just be weak spark causing it to run weird?
Update* swapped a coil with one of the good cylinders and still have same issue. Possible carb problem? Top 2 cylinders do share the same carb.
Update* swapped a coil with one of the good cylinders and still have same issue. Possible carb problem? Top 2 cylinders do share the same carb.