How to adjust briggs & strat 12.5 Yard Machine?

The repair man cleaned my briggs & stratton 12.5 Yard Machine Walbro carbuertor and handed it back to me and said ,"just adjust this screw to adjust idle"? Model# 13AH660F352 machine, model 28T707 , Type 1154E1 so I haven't been able to start this? What is the the postion 6 oclock , 8 oclock 12 oclock, how many screws in or out from all the way in or out? We love our Lawn machine. The first symptoms something was wrong it ran for a short time 10 min. and started losing power and quit running. spark plug clean. The driver said it would slow down and the speed up! slow down and speed up. sprayed carb cleaner in it and it ran for 10 min. and stopped. wouldn't start. so took it to repair man. He cleaned it and handed it to me and said just adjust this, It'll probably run like a charm. Ha Ha ! Please reply Thanks.






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