Motorcycle Questions? Ask a Mechanic.
Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially (and if have not been tried), the prescribed preliminary approach would be; inspect the battery & ground lines and/or check/clean the battery cables + terminals as a primary consideration. Better yet, have the battery externally charged and then LOAD TESTed (even if new/charged and just for the purpose of eliminating it as a suspect).
Additionally, check the starter solenoid. To locate the starter solenoid, start by following the big cable from the + terminal of the battery as it always ends up tied to 1 of the 2 big terminals of the starter solenoid. Carefully but quickly/momentarily, jump the two (2) big terminals. Expect a big spark. This is a bypass of the starter solenoid to enable the starter motor to spin:
Please post back results / observations of the above once tried.