I have a 140 OMC outboard that has 115LBS of compression;I had a problem with it not running on one cylinder when idling but operating normally at full throttle. I replaced one coil installed new spark plug wires and new spark plugs,still no fix spark was a bit weak so I replaced the power pack. The spark seemed to have gotten a bit stronger but the engine still would not run on the cylinder. I checked the reed valves and found that somebody had worked on the engine and cracked the outer housing of the intake manifold. I repaired the crack and reinstalled the carburators now the engine will only run on one cylinder.<br />Any ideas.
