I have tried it with a fully charged car battery but the starter still doesn't turn. Will give it another shot with proper jump cables, i've been using makeshift cables made out of house wiring
since I didn't have anything at hand.
My first guess was the ring antenna but then the starter should not even give the loud knocking sound if that was defective. What about the anti theft alarm (wherever that is)? I am sure that is almost dead as the bike has been standing for about two months.