I have a 1996 Merc 200 EFI and shes a finicky girl. So this is whats going on.
When (not all the time) I start the motor in the morning, or sometimes after I've fished a spot for a while the motor acts like its not on all cylinders. This goes on for a few minutes then you can hear a change in the engine tone and it will then get on plane and run fine.
A few times it has got on plane fine, but then all of a sudden it comes off pad and the motor will be acting like its barely running (wont die unless I put into gear) Then again the engine tone changes back to the normal sound and it get right back up on plane.
When the motor is making this noise sometimes I can put it into gear and move forward but will not let me get up on plane until you hear the engine tone change.
I don't know whats going on. Any help would be greatly appreciated!