Bike won't go into 1st gear but all other gear working fine

[tom90ando]

I have recently changed my chain and sprockets removing the clutch in the process. I have put the bike back together but when I try and go from neutral into first gear it isn't changing. It does change eventually but can take upto 5 minutes of trying. Second, third, fourth and fifth gear are working fine. My bike is a Lexmoto LXR 125

[TimR]

Did you remove any of the gear linkage mechanism  ?

 

You may not have aligned it correctly 

[Mississippi Bullfrog]

Is the clutch dragging slightly? Bike clutches usually show some drag due to their design but if the clutch isn't adjusted right selecting first will be harder.