I take it you are just shotgunning this "no spark" issue and not doing any real troubleshooting. You have already bought a CDI box and new spark plugs and are now looking for an ignition switch . To prove the ignition switch is bad simply disconnect the two MAGNETO wires. With those two wires disconnected there should be spark. If not, you have a different problem. Troubleshoot the issue -- don't just keep buying new parts. Bad wiring may be the problem. What happened just before the no spark situation happened. We cannot help much without details.
