I have a 1998 magnum 425 runs good till half throttle then backfires/loss of power. I have cleaned the carb twice, good fuel, good compression, cam looks great, bypassed the override, throttle sensor good. when I bought it, it had problems. stator was replaced but not flywheel(missing magnets). replaced flywheel but don't have a tach so I tried to time it painstakingly 1 degree at a time to no avail. besides it wont hit 3500 rpm the way it runs. pulling my hair out HELP. lol

 

You said you by passed the over ride. Did you make sure to pull the black wire from the limiter module itself to defeat it? Plus I'd still check the cam lobe height. 1.276 is considered the max limit of wear. If these are ok,then the problem still sounds like in the stator /flywheel area if you're sure about the carb and adequate fuel supply. You can check the pump out by pulling the fuel line from the carb and cranking the engine over. Should be a steady or pulsing stream of fuel. Air box and filter have to be installed also or it can run too lean and limit mimicking an electrical miss.