675 Bike Won't Engage Into Gears

Your quick shifter is basically a rod, a stiff spring and a microswitch. It either works or it doesn’t.

Far more likely is that your clutch has gone out of adjustment and is causing excessive drag that inhibits gear changes. Check your handbook on correct clutch adjustment. You should have minimal movement at the lever before feeling spring resistance. If there is no slack then you risk clutch slip. Too much and the clutch will not free off.

 

I read that as the gears are moving but the bike isn’t so rather than the clutch dragging it’s more likely to be slipping. He’s taken it to a garage anyway but if he comes back to report the problem I’d say the cable/lever hasn’t been releasing properly and the clutch now has burned out.