Suddenly the self start is not working if the bike is any gear. But the same works fine if neutral. My bike is hero honda CBZ.
What could be the problem? Can i rectify it myself? Or i need to take the bike to a mechanic shop to solve?
If you mean it isn't starting when it's in gear with the clutch disengaged, and it used to start under those conditions, check to see if there's a pin switch on the clutch lever housing that's gotten stuck. If so, then the starter won't be able to tell you've got the clutch lever pulled and will refuse to start. You should be able to fix it by spraying some light lubricant (like WD-40 or a silicone-based lube) down the shaft of the switch. Don't use anything heavy like white lithium grease.