if your Guzzi refuses to crank, chances are you have "Startus Interuptus"
Too much resistance between the battery and Start Relay (dirty ignition switch maybe) 0.1 Ohm is too much, that would drop 5 Volts
The Start Solenoid draws around 50 Amps (50 x 0.1 = 5 Volts)
The Start Relay needs a direct +12 from the battery (optional 20 Amp fuse)