I have a 350 Bruin that will only idle for 30 sec or less and it will backfire through the carb and die. I have checked the valves, spark plug, cleaned the carb replaced the idle mitxture jet screw and adjusted 1.5 turns out and then adjusted out to 3 turns, no change. It runs great with throttle applied. Only acts up at idle. The only thing I have not done is changed my gas. That is next.
If anyone has and idea. Please Help......

Thanks

 

Ok, now I have changed the gas. Still the same. It may run even a minute but it will eventually backfire through carb and die.... Anyone....Please

 

Could this be a coil or cdi issue???? Anybody??????
Thanks in advance
TBS

 

Alright few things it could be.....

Intake leak
Exhaust leak
Wet oil filter or carb
Try 2 turns out on the idle jet then go in from there

 

No intake leak, Carb is two turns out and Air filter and carb have been cleaned. I will take a look at the exhaust. The backfire is very random and now seems to be less frequent. It will kill the motor if the idle speed is too low.
Thanks Sparky

 

If that stuff doesnt work try new plugs.

 

Done that too.
Thanks again.
I may need to take her out and run the crap out of her....When I changed the fuel I did add a little seafoam to the tank.