Double check or better yet post a pic of the wire you removed from the starter solenoid to the terminal bar. Most likely, this has something to do with a ckt bkr tripping and resetting. My thoughts is that when you go forward and increase rpm, the stator starts to charge and something is short circuiting the charging current causing the stator to lose power to the CD coils.
There are two separate circuits in the stator, but since both are laid on the same core or frame, a short circuit on one will affect the other. To confirm this, try going in reverse and increase rpm, the results should be the same, i.e. engine dies and loose power to all components until the ckt breaker resets.
The charging system doesn't start to generate enough electricity until around 2000~2500 RPM.
The other thing you can do to isolate the problem is to disconnect the two yellow wires from the stator going to the rectifier. Make sure you tape them off. Then do a test run again and see if the problem goes away.
