2001 honda trx 300ex (sporttrx)

I bought a 2001 honda 300ex (kickstart) when i bought it the person said he cleaned the carb but still is still hard to start and wont stay long enough, when pressing on throttle it dies, what is wrong? Should i take the carb apart myself and rebuild it, whats the starting points on the air fuel mixture screw and pilot jet screw
Thanks