I just bought a 650r. It is in great shape. The previous owner uncorked it and plated it. after some testing when I got home,and changed the oil and cleaned the jets. the bike is bogging and dieing. some times at idle some times mid rev. seams like it dies when engine breaking. The old air filter had crumbled and some did get sucked in. I cleaned the box and replaced the filter first thing. could some of filter material be clogging a port in the carb? where would I start looking? I also thought perhaps the fuel screw could need adjusting. or a line was pinched. Any ideas?