A single gear shift just means that the throttle and shift function are on the same handle whereas the predecessor had a separate lever for each function. Both use a separate cable for shift and throttle and most have the same cable end connectors....Merc was real good about keeping the rolling brass barrel and making controls interchange with many different models. On figuring out which electrical wire is which, Chris 1956 may be able to help you.
6 wires.....let's see:
1. Battery -, usually black
2. Battery +, red
3. Start power: 12v to starter solenoid when key is in start positon to spin starter.
5. Engine kill: shorts out triggers when ign sw. in off position, yellow/black.
6. Electrical choke power: 12v only when key is pushed in and goes to choke solenoid or fuel enrichment solenoid...later models, black/yellow.
Guessing begins now: That engine used a separate magneto distributor driven by a belt from the crankshaft. It made it's own power so it didn't need power on from the ignition switch (requiring another pin on the engine's electrical connector). Just spin the crankshaft with the starter and it would go on it's own....magnetic induction.
Knowing what I just posted, you can take an ohmmeter or voltmeter (Digital Multi Meter does both) and follow the function to the component and then just wire the connector accordingly. The numbers I listed are not necessarily the correct pin numbers, just a list of 6 required functions to operate the engine.
That ought to tide you over till Chris catches the post, or you ping him.
