Trouble with Trannies..

What bike?

Could be something fairly easy to fix, like the shift shaft return spring has popped out of place.

I had that happen once, and my bike had similar symptoms (except it was stuck in 2nd or 1st instead of 5th).

To fix, I drained the trasmission fluid. Laid the bike on the left side. Popped off the right side cover. The shift shaft extends all the way through the engine, and the spring is on the right hand side.

One end of the spring has a pig tail that keeps the spring from spinning. If that falls out of place, the spring will spin. I ended up putting a washer over the shift shaft to shim the spring and help it stay in place.

Total cost was 1 quart of oil and a washer from my tool box.

My best guess is that the pinion gear for 5th is siezed to the shaft.