I just bought a cheap pit bike, a roketa rds125x. To start it I have to have the choke off and give it throttle ( with the air filter off the little round thing in the carb is open, which means the choke is off correct?) Anyway every time I start it I have to adjust the idle to keep it running. If I shut it off and let it sit for like 20 mins then start it again, same process, choke off throttle then have to adjust idle again. What do I need to adjust to get it to idle right without having to adjust the idle after every start?