2.4L 200 merc acceleration issue

[steplift20]

I had a problem like yours years ago, I would be out and the motor was running fine than all of a sudden the oil alarm would go off and o would lose 3 plugs It turned out to be one switch box that was also hooked to the low oil alarm, changed the switch box and problem solved Also it could be the stator . If you are lucky enought to run the motor on dry land and it happens I bet half your ignition is not firing but you can only check it while it's happening Good luck and the y
Tach issue could be cause by a bad rectifier The big guns Hopefully will give your there thoughts soon