Robert Bond's Home Brew CDI for GT500 A and B Models
Robert, with some assistance from Phil C. in the UK came up with this home brew replacement for the Suzuki PEI unit - cost in the USA for the components runs a bit less than $30.
Schematic and Parts List
Note: the 'G', 'A' and 'K' are the accepted terms for gate, anode and cathode connections on the SCR.
The above circuit replaces the area in the box labelled 'CDI unit' in the diagram below which is taken from the Suzuki shop manual which can be found here.
Breadboard Demo Circuit for Testing
Per Norstedt has a good GT500 ignition trouble shooting guide on his site located here which is worth bookmarking.
Component Parts T and GT