This mower runs fairly well when I can start it. I was having trouble starting the mower, plug clean and had new gas and spark, but was able to get it running again on the first pull. Turns out that over time the gas throttle cable had slipped out from the hold down clamp near the carb. When I fully choked the carb the flap in the carb did not close completely. I undid the clamp and pulled back the cable about 1/2" and re tightened. I made sure the flap in the carb closed completely, which can be seen by taking off the plastic cover and removing the air filter. Any way it was a simple fix to the sometimes 40+ pulls to get it to start.
