I got around to looking closely at the interrelationship between the neutral switch; the side stand switch, and starter lockout switch. I asked around the net and reviewed a lot of VROC archives. Here's the information from all available resources. (The starter switches and kill are addressed separately since they are ON/OFF (open/closed) circuit activators and interrupters, respectively, and are pretty straight forward to check, test, clean, repair and replace.)
OVERVIEW
The Neutral, Side-Stand, and Starter-Lockout switch settings are designed to signal the igniter to continue firing the spark plugs under safe operating conditions. The switches are designed to prevent the rider from accidentally starting the engine with the bike in gear (with the possibility of dropping the bike), and to stop the engine when moving away from a stop with the Side-Stand down to avoid the possibility of pivoting on the Side-Stand and dropping the bike at speed. One switch or a combination of properly positioned switches create a path to ground allowing the igniter to fire the ignition coils. But a combination of one or more open switches will break the circuit to ground causing the igniter to stop firing the ignition coils.
The need to flow current to ground for proper igniter operation makes it difficult to accidentally disconnect any of these switches, and still smoothly operate the bike. If a switch fails to operate correctly, a rider can experience unexplainable problems like the bike not starting, or the engine suddenly dying.
Please note that the clutch Starter-Lockout switch is also a two (2) position switch, but its main function is to bypass the neutral switch/circuit when the clutch lever is pulled in.
INDIVIDUAL SWITCH SETTINGS and EFFECTS
Neutral Switch (wire is located behind the left-side engine cover to the lower right of the engine case)
CLOSED: when transmission in neutral ( transmission not in gear) allowing current to flow to ground and the neutral indicator light is lit
OPEN: when transmission NOT in neutral ( transmission in gear), no current-flow through switch
Side-Stand Switch (located at the top of the side-stand on the frame)
CLOSED: when side-stand UP allowing current to flow to ground
OPEN: when side-stand DOWN, stopping current flow to ground
Starter-Lockout Switch (located under clutch lever)
LEVER RELEASED: Connects to neutral switch circuit and the side-stand circuit.
LEVER PULLED IN: Bypasses the neutral and side-stand switches completing a circuit to ground, allowing the bike to start with the transmission IN or out of gear.
Effects WHEN Switch ARE COMBINED
This IC igniter (R/W wire) circuit must eventually be connected to ground by various switch positions in order to signal the igniter to fire the ignition coils to START the engine and then to allow the ignition coils to continue firing.
The Neutral Switch is CLOSED completing circuit to ground (transmission is in neutral, the neutral indicator light lit, and the transmission is not in gear)
then the engine can be started, and the engine will continue to run. If the Side-Stand and Starter Lockout switches are in proper working condition, the position of the clutch lever (pulled in, or released) and the kick stand (up or down), have no effect on the engine starting and running.
But this all changes when the Neutral Switch is OPEN (transmission put in gear and neutral indicator light is off) because
there is no path to ground through the neutral switch). Now the Side-Stand and clutch Starter Lockout switch come into play. In both cases below, the engine can only be started with the clutch pulled IN. After the engine is started, then the Side-Stand switch position controls engine operation:
with the Side-Stand UP
The igniter continues to fire the coils and as the clutch lever released engaging the clutch, the bike moves forward.
but with the Side-Stand DOWN
and the clutch lever pulled IN, the bike can be started and continue to run as the rider puts the bike in and out of gear. But as the clutch is released with the bike in gear, and the kick stand down, a connection is made to the neutral (open, ungrounded) circuit. With the R/W wire without a path to ground, the igniter stops firing the ignition coils and the engine dies.
With the kill switch on, try starting the engine in neutral with the kick stand down, and the clutch lever pulled in and then released. If no start, then put the bike in gear, pull in the clutch lever, and try to start the engine.
If the bike does not start, then raise the bike to vertical, raise the kick stand, pull in the clutch lever, and try to start the engine.
These manual tests can be done quickly and can bypass possible problems with the clutch switch, neutral switch, or kick stand switch.
TESTING INDIVIDUAL SWITCHES
Neutral switch test
OPEN: transmission in gear, out of neutral, indicator light off
CLOSED: in neutral, transmission out of gear, neutral indicator light lit
With the transmission in neutral and ignition ON, but the engine not started, connect a volt meter in series between the neutral switch and the disconnected wire to the switch. If the volt meter does not read 12 VDC, the switch is bad.
BYPASSING: Connect the neutral switch wire to any available ground point on the engine or frame.
NOTE: BYPASSING the neutral, Side-Stand, or Starter-Lockout switch carries a risk and will endanger a rider. Remove the bypass as soon as possible to avoid injury.
Side-Stand switch Testing
OPEN: Side-Stand DOWN
CLOSED: Side-Stand UP
Access the two Side-Stand switch bullet connectors located to the front/right of battery. Raise the bike up off the Side-Stand on a jack or other means so it is in a safe upright position. Use a continuity or ohm meter to test the Side-Stand switch in the DOWN position (no continuity, infinite ohms), and UP position (continuity, 2-5 ohms). If the switch fails either of these tests, try to clean it up with WD-40 to remove road grim and dirt that can collect under the rubber cover. Or replace it.
BYPASSING: The Side-Stand switch can be set to ground regardless of the Side-Stand position by connecting together the pair of male/female bullet connectors on the (BK/Y and G/W) wires running up to the main wire harness.
NOTE: BYPASSING the neutral, Side-Stand, or Starter-Lockout switch carries a risk and will endanger a rider. Remove the bypass as soon as possible to avoid injury.
Starter-Lockout switch testing
PULLED IN: Bypass neutral circuit
RELEASED: Connects to neutral switch and neutral indicator light circuits
Remove connector and using an ohm meter or continuity tester, connect a probe to the center male spade connector. Place the other probe on LEFT spade male connector. Low ohm reading with lever released is correct. Infinite (or open circuit) pulled in is correct.
The RIGHT spade male connector should test opposite (low ohms lever pulled in. Infinite ohms (or open circuit) lever released.
If the Starter-Lockout switch tests differently, it should be replaced. A lot of grime and corrosion can collect on/in the switch and on the contacts. You might be able to get the Starter-Lockout switch to operate properly for a while longer if you open the switch and clean out any accumulated dirt and remove any corrosion from the contacts. The switch body halves are a snap fit.
BYPASSING: If you are on the side of the road and need to get to service, you can try to jumper the switch at the removable snap connector. Use a piece of wire or a paper clip to jumper the center female slot ( the BK and the BK/Y wires). If you can't make out the wire colors, try switching the jumper to the center and either outside connector slot, then the other outside connector slot.
NOTE: BYPASSING the neutral, Side-Stand, or Starter-Lockout switch carries a risk and can endanger a rider. Remove the bypass as soon as possible to avoid injury.