I just got a used 1996 300ex thats smokes and burns oil. Not sure if its the valve seals or the piston and rings. I was wondering how hard is it to take the top end apart. do you have to do anything besides unbolt and pull apart like a remove the cam or anything like that. I am taking the top end to be checked. I am used to a 2 stroke work first 4 stroke. any help would be great.