Check the ESA
Check the ESA
Since it stumbles in gear, you should check to make sure the transom shift cable is adjusted properly and the switches are not being activated when it is in gear. The rollers on the switches should be in the middle of the notches when in forward neutral or reverse, they only get activated while shifting. It stops when you push the trim switch because the power drain on the ESA will not allow it to work properly. Check the switches to ensure they are working and are not hanging up after activation.
Do not make any assumptions about the condition of the motor or drive, you should do a full diagnostic on the engine (compression check, static and full advance timing, check the condition of the plugs, check for proper carb float level, fuel pump pressure, non-ported vacuum reading at idle) as well as making sure all the shift mechanism is properly adjusted. There are many things that can cause your symptoms and you need more information, that's where the diagnostics come in.
Good luck and let us know what the problem was and the solution.
