I have searched around this site and have not found what i am looking for. I want to find info on someone who has upgraded a single cylinder BRP 650 rotax engine. I am at the point where I have to send my machine into a shop, cant get her started. I have some other posts asking questions and describing problem...got some feed back. At this point I am sure it is internal, maybe timing, not sure. Point is, if it involves taking engine apart and replacing gaskets and so on...then this is the time to modify the engine to uprade performance. Does anyone know where I can go or look...research. I have emailed Mr Rpm....but he has not responded.....so please ...any help would be greatly appreciated