[update] Well I cut down the forest to get to my shed and brought the mower around front to work on it. I lied above, it has been almost 5 years since last started. I siphoned out the old gas first, then opened the air filter compartment, sprayed some carb cleaner into the carburetor opening, replaced the filter, added a small amount of fuel stabilizer to the gas tank and filled her with gas. I checked the oil and it looked clean and full. When I tried to start it, it didn’t even sputter. So I removed the air filter again and sprayed more cleaner. Leaving the air filter off I pulled the cord several times and got it to run for about 20 seconds. Sprayed a little more and replaced filter. It start with just 3-4 pulls and stayed running. I cut a small patch of grass and then stopped to rest inside. When I went back out it started with just one easy pull. I was able to cut most of my side yard but the mower stopped running. I still had plenty of fuel in the tank but it would run only for a few seconds. I let it (and me) cool down for about 30-40 minutes, it now turns over on one pull but immediately stalls out.
Any ideas? Could it be more gunk in the carb? I’ve stopped for now because I’ve done enough for today and thunderstorms are closing in. I will try again this weekend, I’ve got dr appointments tomorrow and Friday and we’re due for some rain anyway.
Also, what is a safe and environmentally responsible way to dispose of old gas? I have it in a sealed glass jar right now and it looks clean with no water. I was thinking of feeding a little at a time back through the mower with each new fill up. It is only about half a quart.