i have a bolen 150 weed trimmer. it starts runs for 5 secs shuts off. over and over. if i close the choke it will stay running. open choke it runs fast shuts down. gas is good line is good new spark plug. the only thing i havent tried and i am going to is lossen the gas cap. i take the lines off and gas wont drip out unless the gas cap is loose. I . carb is clean. new lines new filter