I am a newbee, here is my problem. china girl 80cc wants to 4 stoke until 12 mph, the is no adj. on carb except idle speed. I don"t know what carb. I have all it says on is" speed". I have maybe 50 miles on the motor. I started to run 40x1 mix with Yamaha oil. is this normal or will it get better when it gets fully broke in? I know someone here can help. thanks.