will not shut off with key and safety is gone

i have a 28 evenrude svo? it has omc controls it starts shifts ok but you can shut key off or take out it stays running also the safety on side of control does not have the plug and string attached but runs fine i think some one lost safety and bypassed it so it stays running and drains the battery down if i leave battrey connected then i cannot start next time (a few days later )because of dead battery will not crank electric start i leave cable shut off stays charged fined and if i pull start with dead battery it charges fine but i have to pull gas hose off to shut off which leans out motor before it shuts off i know i should not do that but no other choice please help i have very little money so i have to fix myself thank-you for any help