I just got my 9.9 Johnson back from the repair shop. It quit while on Quabbin and I would have been stranded had it not been for my electric trolling motor. The culprit was old gas. I had used a stabilizer and another additive and it didn't help. The mechanic told me he wouldn't keep gas longerr than a month.
Use sea-foam and you will get shelf life for a year. Today's gas only has a 30 day or less shelf life to it. I use sea-foam in anything with a small engine up to my vehicles. This is the best stuff I've seen.
I bought a generator back in the ice storm a few years ago and i still have same gas in it with sea foam and i run it every month. My auger is the same i start i started it up this year with last seasons gas and off i went. I also replaced all my fuel lines and use an additive called startron for older motors. The new gas will eat the insides of old fuel lines and then you will be definitely stranded.
JMO