this is a question for anyone that has the 416 kit on their 400ex. how long did it take to tear the engine down...how long to put it back together? I am 15 and im thinking about putting a 416 or 415 kit with hotcam stage 2 on my 2003 400ex and i have limited space to do the work and probably not much time. If nothing else i might have to send the engine off for someone else to do, not because of lack of knowledge but limited space. thanks for your thoughts.