Re: 1981 johnson 25 hp electric
Its hard to understand the question, exactly which end of the harness, at the ignition key or the engine end?
A factory manual wouldn't hurt.
www.kencook.com
My engine is a J150 , if the wiring codes are the same, you might fry something if they're different though.
Solid purple is tach wire from rectifier
purple and white is choke
black is ground duh!

,see if theres a black wire at the starter solenoid opposite the yellow/red on the small terminals, if not it probably is that.
yellow red is starter solenoid and powerpack ( at the engine end obviously)
red being power feed can be any of a few places, starter solenoid, rectifier feed or tilt/trim power feed. My guess is the starter solenoid if its not already there, look for where it isn't already in place.