bike runs perfectly from stop to 3900 rpm every gear neutral and all. dies at 3900 rpm and starts back up (while riding) no back fire nothing starts back up just fine. new coils new regulator new battery new fuel pump clean carbs full system electric tests have been performed and everything looks as it should. normal resistance and no voltage drop. not sure on the year but an early 2000s shadow 1100 not my bike helping a friend.