Hi Go,
Don't do it! Only advance it one tooth. For a while a couple of Whizzer dealers were suggesting 2 teeth, but the end result was less than stellar. Because of the piston cycle, the intake was open too soon and destroyed the intake charge pulse at low to midrange. The top end paid a price also with almost 800 RPMs less.
Even if you advance the ignition timing it won't work correctly.
A few facts concerning advancing the ignition, it can be easily altered from 14 degrees BTDC to 23 degrees BTDC. If the trigger is moved past the 23 degree BTDC, the magnet sync will decrease the necessary voltage and will lower the spark [or totally remove the spark]. In order to advance the timing, simply remove the trigger plate on the flywheel, move it forward [counter clockwise] until the rear edge is now covering 1/2 of the original hole. Mark the spot, drill & tap [5 MM threads]a new hole, insert screw thru plate[use loc-tite], tighten to flywheel. The best way to remove the original trigger plate screw is to use pliers and twist the plate as you loosen the screw [prevents destroying the screw].
Hope this helps,