Disconnecting the seat switch guarantees a no spark condition with the brake released.
The seat switch connector has grounding tabs that close when disconnected, thus grounding the kill wire
.ANYTHING that grounds the "M" terminal of the key switch kills spark!

Seat Switch is normally closed and is opened when occupying the seat.

In the Owners manual, there is a schematic. (page 33/56)
On the lower left corner of that page is a "truth table" of what connections are/aren't made in the various key switch positions.

Thanks BK, good info.
Can you tell me which poles in ignition switch, do I test for continuity?

As I stated-
In the Owners manual, there is a schematic. (page 33/56)
On the lower left corner of that page is a "truth table" of what connections are/aren't made in the various key switch positions.

IF you don't have an OM, click the link

Here is a link that might be useful: OM