I am new and think I posted this in wrong spot...oops

Hello my name is Bob and live in Arizona..Just got a Twister go kart for my grandson and trying to figure out how many cc's it is... The engine code is 157FM . Also, the engine makes a POPPING noise as i let go of the gas... Any help would deeply be appreciated...Thanks, Bob

 

Your in the Chinese section..your good.

150cc is more than likely it.. popping as you slow down is either a exhaust leak in the head pipe area. or its jetted lean..

 

Thank you very much for he help i will try that today . I hope it is just a header leak. Touching the carb. scares me for 2 reasons 1. know nothing about it . 2. i am legally blind can see a little bit but not much...If it is the jetting on the carb. Is that hard to do , or is it just turning a screw a couple of times? Do I have to take out the carb. to do this? Once again thank you....