I ran 16/41 for a while and liked that , now I'm 15/40 with a 190/55 rear tire , it's about the same. These won't do 200MPH without motor work. Put a meter on your battery , bike off , then running. You should get over 12v off and around 14v running. If it's not charging , next would be ohming out the stator windings. If the windings are OK , it's your voltage regulator.