Newbie needs Help

[alandi]

Hello Forum Hope someone can help!!
Recently bought my son a DAP chassis and fitted a 2nd hand GX160 engine
I cleaned the plug and stripped the carb (was full of varnish and debris!!) and it runs very well untill.... After about 15 mins use the engine starts to bog down and splutter a bit as if the timing was out. I turn it off and put a few drops of STP fuel system cleaner in the carb top and rev the bejesus out of it then it runs sweet again!! I have replaced the fuel incase it was stale but it still misses when warm! also do i need the choke switch in the same position as the fuel tap when it is running normally??
Thanks in advance for any help
Cheers
Alan UK

[hd4ou]

sounds like the vent is plugged up. tear the carb down and clean it. if not those carbs are fairly inexpensive so just buy another one.

[alandi]

Thanks for that will get on it ASAP . Currently off road dur to him hitting a rock and breaking sprocket carrier.
Thanks again
AL