You say "starter button not working" ! Is that a typo error? If not, then that's the fault, the wiring or switch needs repair or replacement!
Here's the basic starter circuit diagram attached. Highlighted Red is the Positive Voltage feed for the Relay Coil the Green Highlighted is the Grounding side for the Relay Coil.
- At Ignition Switch On, are all Indications, Lights, Fuel prime, Normal?
- Have you confirmed Fuse D 10amp Starter Fuse is good?
- Have you confirmed the Neutral Switch is working? Is your Neutral light on?
- Have you tried a Sidestand Up, Clutch pulled in start?
If you remove the red plug from the Starter Relay and probe the Red wire connector and the Yellow/red wire connector at the red plug you should have continuity provided the Ignition is On, the Fuse is ok, the Kill Switch is in RUN and the Starter Button is pressed.
Another possibility is an open circuit Clutch Diode. But this will only effect a Neutral Start, Not the Sidestand Up, Clutch in Start.
To verify your Starter Relay function, you could use a couple of test leads from the battery, remove the Red Plug from the relay then probe the test leads to where the Green/Red wire (Ground) and the Yellow/Red wire (Positive) would normally go to on the relay. Each time you make contact to the terminals the Starter Relay should energise and starter motor should run. MAKE SURE IF YOU DO THIS YOUR BIKE IS IN NEUTRAL AND PREFERABLY ON THE CENTER STAND.
Let's know how you get on.