My son's 200x is having transmission issues and we can't nail it down. When under power in 3rd or 4th gear it is acting like the teeth are jumping, you can actually feel the trike jerk. We pulled the trans this weekend and everything is okay and the clutch is within the service limits. After we put it together it ran fine for awhile but then started again. We're going to meet a group to ride next weekend and would like to get it fixed. Any ideas on what it could be or what to check next?