Gz250 starts but takes a while
 

Always my bike would start first try in a split second but lately I tried it cold with full choke and its like I'm trying it with none on a winter day.(it's summer) takes a while and after 10 seconds or so of fiddling with it it fires up?!?!?

Hi can anyone help my bike has always fired up right away but lately I trid it with full choke cold and it's like I'm not using it at all takes about 10 seconds to fire up, I'm worried if weather gets colder I might not be able to start it

Unscrew at the carb end & check that the plunger is moving & clean.