Silly question #1. Are the plates in the correct order?
Silly question #2. Have you actually tried putting it in gear (with the rear wheel off the ground)?
With the engine stopped, put the bike in top gear. Pull the clutch in and you should be able to rotate the rear wheel by hand. There will be some friction due to the plates and the box. Release the clutch and the wheel should lock up.
Failing this start the engine, pull the clutch in and put it in gear, the wheel shouldn't turn too fast. If it does turn, try applying the rear brake, the wheel should stop.
There are several things you need to check. Is the cable the correct route, (no sharp turns or kinks) is ti the correct length, both wire inner and outer sheath (If it is OEM i'd take this as ok), is it adjusted correctly, do up the adjuster until there is no freeplay in the lever then back it off until a bit appears. are the plates in the correct order and are the springs at the correct tension.
