Quote Originally Posted by lewnor View Post
Anyone have problems in 5th gear? I would shift in to 5th and would start to lose acceleration.This would happen at 55mph and would come and go. I am going to check the fluid level in the morning and wanted input on other things to check.
Already some great suggestions for you.

Are you sure it was actually getting into 5th? Not stuck in 4th, or somewhere in between? How was the motor responding?

How's the clutch adjustment?

How tight is the chain? Can you move the rear wheel freely on a jack?

Any leaks at the air filter?

Intermittent problems always make me think of wiring. Hows the plugs at the ignition bits? CDI connector?

Good luck, let us know what you find!