Have you actually had the engine running while you shifted it since you worked on it? It might surprise you.  Your troubleshooting addressed the most common area for failure to shift.

If you look at diagrams on the transmission, these transmissions couple and decouple the gears with pins and pinholes in the sides of the sprockets to determine which sprockets are actually driving. If the pins aren't aligned and the shafts aren't spinning, the transmission might have trouble getting the pins to drop and engage but would be fine at the ends of the shift range.

Also, these don't shift like other bikes. Don't stomp it as this is what causes damage and don't expect it to want to complete the shift for you. False neutrals between 1st and 4th aren't uncommon of you ride other bikes and have certain expectations. The first portion of actuation is clutch and the latter is actually positioning the transmission.  Because of this, play in the shift arm is not that critical.

Go for a spin. Try shifting gently but deliberately until you hear the gears mate and deliberately release the shift lever.

Last Edited By: mrmiji Jul 26 11 4:23 AM. Edited 1 times.