http://www.msdpowersports.com/single_cylinder.html
the msd single cylinder cdi module could sole the proble, i looked at the wiring diagram and it doesnt seem too bad.
Group A connectors:
ORANGE Connects to Coil positive (+)
Brow/OrangConnects to Coil negative (-)
Violet On/Off, connect to switched +12 volts
Black Ground, connect to battery negative or crankcase ground
Red Connect to battery positive, 12 volts
Group B connectors:
Blue Launch RPM Limit, the launch rpm is active when connected to ground
Trigger Pickups
Green Magnetic pickup negative
Violet Magnetic pickup positive
See Figure 3 on page 4 for information about pickup polarity.
Note: The mag pickup wires are never connected when the White wire is used. And vice-versa.
White Hall Effect trigger input or kill switch to ground
Brown/White Timing Curve B Select. When connected to ground, Timing Curve B is active
Throttrottle Position Wiring
Yellow TPS input signal
Black TPS ground
Red TPS +5 volt signal output
L
ED An LED indicator will be On when there is valid trigger input and can be used as a static ignition timing indicator with the Hall Effect pickup input