Hello. I have a mini bike with a new Predator 212 stock. I broke it in 40min idel and changed the oil then got about 4+ riding hours before full throttle. It ran great the whole time except start ups and that's why I got a gx140 e-tube and .36 jet. I put that in along with a uni air filter and spark plug. It starts first or second pull and will idle as long as I let it but if I take it for a ride it only runs for about 5min the shuts off. I have already unplugged the low oil wire and used in line gas filter for the 2 breather tubes. I have to go back to choke on to start and when I put choke off it dies. I think maybe it's the cheap carb and should I just buy a new one or is it the re jet? Also it's not the gas cap it is venting.
I had this problem a month or two ago just after installing the new jet and e-tube. I would have to keep it on choke or else it would die. My problem was when i was putting the carb back on, I had over tightened it and it cracked the insulator gasket(big black plastic one). Replaced that and good as new.