my 05 450r will not crank unless you choke and when it starts and if you turn the choke off it will try to cut off. in first gear it putters and trys to die but if you open it up it will run fine. you can get it to run if you keep the choke on while you ride but i dont want to ride it choked. it has a full HMF exhaust on it and i was thinking maybe i need to jet it but im not sure. does anyone know wat i can do to fix this?

 

Definitely need to rejet.

 

adjust your valves and rejet

 

thanks