This feature is called "Positive Neutral Finder" and is available on several different makes of bikes. It
WILL NOT shift into 2nd gear unless engine & rear-wheel is spinning.
Cycle World 1985
Postive Neutral Finder Mechanism
Along with other safety features such as Kickstand position detection, clutch-lever position detection, neutral-gear detection in AND/OR logic circuit to enable/disable starting bike.
3. Not sure what you're asking, clutch cable adjustment? There's no cable for shifter, it's simple push/pull rod on left side shift-lever. Just lift it up until it clicks into neutral. Then push bike around to confirm it's in neutral. No clutch action needed for any of this. Then start it up once it's in neutral.
Oh yea, there's interlock safety switches that needs to be set properly:
- neutral switch grounded when in neutral
- kickstand switch grounded when kickstand is up
- clutch lever switch in squeezed position (3-wire 2-states)
When all those are aligned properly, only then will start-button crank starter. Very common to have kickstand-switch out of alignment so kickstand doesn't push on button properly.
https://faq.ninja250.org/wiki/Unders...afety_switches