I replaced the gears and it still surges. I decided to put the board an EP-5 i have.
I gutted the reverser and horn circuit boards. I wired it temporarily to make sure the motor was wired properly for forward/reverse. If it is wrong, just swap the motor wires.
Once everything was correct, I soldered and heat shrunk all connections
I usually glue a 1/8" plastic tube to the roof to hold the antenna.
Brendan