I bought my son a 125cc Sunl and it has been a headache. I bought it off of craigslist with carb issues. I've had it two weeks already and Tonight was the first night i made TWO SUCCESSFUL trips around my block and put it back in the back yard. I went back out about 10 minutes later to ride again and it goes about 10 to 15 ft and shuts down. It starts right back up without incident everytime but it stalls out again after another 10 or 15ft. Can someone please help me i'm going to pull my hair out of my head and throw this thing in the pool. ( My pool is inground lol) Also i have the jets set to 1 1/4 turns out, is that not enough or is it too much? my float and needle are clear my jets are clean as a whistle. ( I pulled the ENTIRE carb apart). Someone please help..

 

is it bogging down when you increase throttle?
OR, when idling/riding, does it just idle down and die? no bogging?
could be a couple of different items but here we go:
1. float could be stuck almost closed and it is emptying out the bowl, running out of fuel and dying. it can't meet the demand.
easy fix, clean the float/needle seat/valve inside the bowl.

2. is the fuel tank vented? does it have a hose coming off of the cap or does it have a vented fuel cap? it may be plugged/clogged/choked off and not allowing the fuel tank to breathe. thus acquiring equilibrium with the lower pressure carb/intake and becoming stagnant. high pressure flows to low pressure. it may be that pressure becomes equal after time.
easy test here: run quad, just idling or whatever with fuel cap OFF and see if it dies.

report back when you can.