I have had my '71 merc 650 4 cylinder (ser:3155373) for over 10 years. I have taken good care of it and it has performed well. A few years ago I made the mistake of disconnecting the battery while running. This damaged the trigger unit. Recently I replaced the entire ignition system with new old stock and carefully rebuilt the carbs with a quicksilver kit.
The engine will start following the normal cold-start procedure, but it will only stay running if I keep the warm-up lever way up and will die if I try to back off on it.
I am an electrical/mechanical engineer and I don't work on outboards very often so I am trying to figure out how to proceed in order to troubleshoot this problem.
I have service manuals for this engine but they don't seem to address this issue. I have spark and compression and never changed the timing - only replaced the timing belt per spec - so I am thinking this may be about carb adjustments. Any ideas would be welcome.
The engine will start following the normal cold-start procedure, but it will only stay running if I keep the warm-up lever way up and will die if I try to back off on it.
I am an electrical/mechanical engineer and I don't work on outboards very often so I am trying to figure out how to proceed in order to troubleshoot this problem.
I have service manuals for this engine but they don't seem to address this issue. I have spark and compression and never changed the timing - only replaced the timing belt per spec - so I am thinking this may be about carb adjustments. Any ideas would be welcome.