Good morning, maybe someone can help me here. I have had massive problems with my John Deere 111 seat mower with 13ps Briggs & Stratton machine since the winter. I can only mow for a few minutes, then the part goes out and then it goes very hard. I have cleaned the carburettor already 2 times, then installed a new carburettor, spark plug replaced, air filter is new, oil is new etc. To adjust correctly I still lack a speed meter, but this is sc hon ordered. I only thought I could adjust it with the instructions on the manufacturer’s side at least about that. I start it and let the trekker run warm, after that I set the small clean. I can drive back and forth for minutes on the yard without something happening. As soon as I mow it is as bewitched. I mow a minute, sometimes a quarter of an hour and then he goes out and only lets himself start with help. He then runs very unevenly, the spark plug is black, u And the float chamber full of gasoline. I have a screw to adjust for the idle and the second one on the Walbro carburetor is for the mixture. If I understand that correctly. I can now twist the mixing screw as I want, nothing changes at all. I don’t know any more, maybe someone else has an idea here. The meadow is slowly growing over my head, because I’ve been doing it for 4-6 weeks now.