i recently purchase my son a bike last year .it ran fine all summer long but just recently it got pretty cold and when we started up in the morning it would start but stall out when we shut the choke off just recently i noticed that a red light was flashing on the reverse is this a big prob;em or an easy fix.also he has squeaky brakes easy to fix or fig prob.
thanks for the help

 

let it run longer when you first start it up with the choke all the way out, and when you push it back in, do it slowly.
as for the red light, i think all of them do that when in reverse as kinda showing the rev limiter is kicking in.
There are alot of threads on here about the brakes issue becuase it happens to almost all of them, but i dont know how to fix it. Maybe new brake pads?

 

Have you tried shutting off the choke a little at a time and giving it gas to keep it running. If you can keep it running until it gets good and warmed up will it idle on it's own then?

The reverse light can be caused by more than one thing I think. If you over rev it in neutral that will cause it to blink. I think I have also see mine blink when I tried to put it is 4x4 or diff lock while moving. Does it do it all the time or will it stop if you turn the quad off and restart it?

 

if warming up for a while dosnt solve your sputtering problem, then your pilot jet may be gunked up. it happends over time; just clean and reinstall makeing sure to count the number of turns in or out it is.

 

Before you tear down the carb, try some SeaFoam in the gas. It's available at auto parts stores.