You'd have to post up a wiring diagram.
Running a switch in series with the lill won't do anything because they kill it when they ground. Otherwise, even removed, they run. I imagine it kills/breaks power to the CDI or coil somewhere.
Easy to do, just post up a wiring diagram but you may have to get some connectors or splice some wires; I'm not sure but you don't have an 87 harness so you are probably missing the connection...........
All our government does is distract us while they steal from us, misspend our tax $ and ruin our country