Re: 1971 Merc 800 - Run without control box ??
On the stbd side of the engine, the side that does NOT have the distributor wiring connected, you'll see a white terminal and red terminal on the CDI box (power pack).
Normally, the red terminal is "hot" all the time when the control harness is connected to the battery.
To fire off the ign requires not only the red terminal to be "hot" but the white terminal on the same side of the box "hot".
So, if you connect the positive (red) terminal of a battery to the red and white terminals on the power pack, and the negative (black) side to engine ground, you'll have spark.
The next problem is the starter. You can put 12V directly on the starter terminal, but you've got to watch out for sparks! Best way to run the starter without a harness is to connect +12V to the starter solenoid (the battery side, not the starter side), and of course neg battery lead to ground.
You'd energize the solenoid by applying +12V to the small terminal on the starter solenoid that has a yellow wire connected to it.
Or, if you're ambitious and have strong arms, you could try and rope start it! Not for the Faint of Heart, though.
Well, that's about it, watch for sparks and Be Safe. Don't hook up anything backwards or arc accidentally to electronic components or you'll likely fry them! Make any connections 1st then hook up battery last.
And Do Not, repeat Do Not, ever apply 12V to the terminal on the other side of the power pack, where the white wire coming from the distributor is connected. Just about guaranteed to fry the pack and the distributor!
Oh, yeah, I forgot, you'll need to manually choke the beast to get it going.
HTH & G'luck...........ed
