I have a 2004 honda foreman 450 when you start the bike it idles fine put it in hear and ease into the throttle it will run fine but anything past half throttle it stalls and back fires there’s no smoke I put new piston new sleeve new head and cleaned the carb and changed the plug new fuel line and cleaned the tank when I put the new head I used the old valves they seamed to seat fine does anybody have an idea what I should do next