I found a DF9.9 manual. Timing is set to 5 degrees ATDC at idle. The electronic ignition if working properly will advance the timing to 30 degrees BTDC at high speed also called WOT or wide open throttle. This is done by the pulsar coil sending a signal to the CDI unit CDI stands for condenser discharge ignition.
Update August 2021: There is an electronic switch mounted on the mechanical gear assembly wired to the electronic ignition module. The switch is closed when the motor is in neutral and open when in gear. When running in neutral and the switch closed the engine timing is advanced and runs at 5 degrees after top dead center. When placed into gear, the switch opens and the electronic ignition advances the timing to about 30 degrees BTDC (Before top dead center). The electronic module then advances the timing which also increases the RPMs as well.
You can test this out like cousin Greg and I did by disconnecting the switch connection while the engine is idling. The engine will rev up significantly and your timing light will show you that the timing has been advanced to 30 degrees BTDC. It did not appear to us that the timing advance was related just to engine speed as we did not observe a shift in timing based on speed. The only timing change we observed was affected by the open or closed position of the gear position monitor switch.
For reasons we have not sorted out just yet, our motor has trouble holding a very low idle in neutral. Since the RPMs would increase by 500 or more RPM when placed in gear, this presented a challenge to maintaining a low forward or reverse speed when running. Am considering adding a manual switch to bypass the gear position monitor, this would override the timing advance.
Guy Simonian
