Have been working to restore a 225 to top running order. After running well for a four or five hours after launching the boat in Alaska, one of my 225s developed an intermittent but continuous "knock" at idle and wont turn up to full rpm at cruise. I completely drained and replaced fuel with fresh, replaced filter with new racor, drained all settlement bowls on engine. Replaced all spark plugs and started engine, same knock. Suspected perhaps a coil to be at fault so I swapped all six coilsf from starboard engine which runs fine on all cylinders. Same knock after all coils were swapped.
Looking for suggestions on where to go next. How are the coils controlled and is there a way to see if the signal to the coils is not making it short of disconnecting them one at a time to see if the engine runs differently? Is there a knock sensor that could be reset? I have the shop manual but don't see any trouble shooting entry for the symptoms I am seeing here.
Thank anyone in advance for their time, chawk_man and honda_dude in particular have been very helpful thus far. Both units are on and running fine after extension case and bearing replacements.
Looking for suggestions on where to go next. How are the coils controlled and is there a way to see if the signal to the coils is not making it short of disconnecting them one at a time to see if the engine runs differently? Is there a knock sensor that could be reset? I have the shop manual but don't see any trouble shooting entry for the symptoms I am seeing here.
Thank anyone in advance for their time, chawk_man and honda_dude in particular have been very helpful thus far. Both units are on and running fine after extension case and bearing replacements.