every spring i can get the other 2 sportsmans fired up and running,but when it comes to my sons 325 trailboss i can never get it running,it try to start but it runs for about 30 seconds with the starter fluid then it stalls,could it be air in the gas line?

 

Try cleaning the carb and pilot and main jet,plus may need to replace the needle and seat. Once you get it running good,pour in some STABIL in the fall and you wont have problems next spring! Good luck

 

the fuel filter, then the carb may be dirty as well if not starting. if you start the bike w/ staring fluid and it doesnt stay running on full choke, at least see if the fuel pump is pulling fuel to the carb.