Agreed^^ Seen that before. Also make sure that your air filter is clean. Hold it up to a light and if you can see light through it. Also maybe try running with no air filter to see if you need a higher air flow filter. Could be something as simple as that.Look for a blockage in the intake or exhaust. I had an old Yamaha 200 wheeler years ago. Mud dobbers clogged the intake snorkel. It sure woke it up!