Small Engines (Lawn Mowers, etc.): simplicity 6216, starter solenoid, horse model

Question
i have an older (1986 i think)simplicity 6216 garden tractor,will run for about 10 min. then stall out and have to play with choke to keep it running.have replaced fuel shutoff solenoid,and starter solenoid,but nothing changed not sure of solenoid,still wont start with key.i have no manuals on this tractor so am at a loss.mfg#1690709 b&s 16 horse model#402707 any info would be greatly appreciated

Answer
If playing with the choke will keep it running it is a fuel problem. The first place I would look is the fuel tank and pick up tube. You also need to find a new parts supplier. Any dealer who would sell you a fuel shutoff solenoid is only concerned with making money, not customer satisfaction. In my shop we work on 3500 mowers a year and have NEVER replaced a fuel shutoff solenoid in 15 years.
Clean the carb, replace the fuel lines and remove and clean the fuel tank and pickup tube. I think you will be pleased with the results.