starter switch? Do you mean a kill switch (Stop Switch)?
a few wiring diagrams near the end of it..
I see nothing but the kill switch.. 3 wires, two black and a brown.
Study the wiring diagrams in that manual .. pick the one that is closest to your bike's wiring.
The black Stop Switch wire splices off of the BLUE condenser-ignition coil wires.. When that black wire is grounded (with the Stop switch) it grounds the blue condenser wire and you cannot get a spark.. it kills the engine.
Try disconnecting the black kill switch wire down near the engine. This will bypass all the wiring in the bikes frame, incase there's a problem in that wiring.. and the engine should start.
I can't help further cause i dont have that bike .. but the general idea is to disconnect and isolate the bike's frame wiring.. disconnect it from the coil / points / condenser. It's usually necessary to disconnect only one wire.. in this case the black kill wire..