49 cc pocket bike magneto bolt keeps backing out.
 

Just got the bike and am in the middle of getting it ready. I put a new coil on and now it works. I put a bolt in place of the torxs head bolt so I could use a drill to turn it over while diagnosing so I wouldn't pull my arm off. It has a lock washer and locktite but it still backs out. I have no problem putting the original bolt back in but then I'll have to put on the pull starter and will have no way of knowing if that bolt is backing out until it's too late. Any suggestions?