Ok, here's diagram of how power gets from battery through starter-solenoid. Also test-points of interest. Notice that battery-power just bypasses solenoid through 30-amp fuse on its way to ignition-switch. Even defective solenoid will send power to ignition-switch.
TEST-POINT 1 - battery positive terminal: With bike OFF, battery provides all power for starting. Simple enough to measure directly at battery-terminal as control.
TEST-POINT B - solenoid inlet terminal: Other end of battery-cable. Would be best to trace battery-cable from positive-terminal and find other end. Measure metal tab at end of cable,
it should be same voltage as other end of cable at battery. Also measure at
terminal-B of starter-solenoid where you have battery-cable connected. Should be exact same voltage as at battery.
TEST-POINT - fuse inlet: this just verifies fuse is connected to inlet terminal-B of solenoid.
TEST-POINT - fuse outlet: this actually tests that fuse is good and conducts electricity. Should be same as battery.
TEST-POINT 2 - solenoid output: Measure upper-right terminal of 4-pin socket. This takes outlet from fuse and sends it to ignition-switch. Should be exactly same as battery.
Note that there's no switches or relays or anything involved in circuit up to this point. Everything is tough, solid metal or close-to-solid metal. Most sensitive part is 30-amp fuse and is actually difficult to blow. Battery-power automatically flows through positive-cable to starter-solenoid terminal-B, through 30-amp fuse, out white-wire to ignition-switch passively.
TEST-POINT M - solenoid outlet terminal: goes to starter. There should be
NO, ZERO, ZILCH, NADA power at terminal-M on starter-solenoid with bike off. Power from terminal-B
only comes out to terminal-M when starter-button is pushed and all circuits connected properly.
So, IF you are NOT getting power to terminal-B of starter-solenoid, THEN positive battery-cable is bad. OR it's connected to terminal-M instead. Measure voltage at terminal-M. Simplest test really is just to trace battery-cable from positive-terminal and measure other end and see which solenoid terminal it's connected to.