The fuel is stale.
Drain it all out and smell it.

I have found ethanol in “91 n ethanol” gas before. If you are having ethanol problems, seafoam can actually add to them. It has a lot of ethanol in it to suspend water and move it through the system. That’s why over treatment is not always better with seafoam. I was a sf user for years, last 10 years or so I’ve used Startron Enzime Treatment and everything starts, even after years of sitting.

I don’t have time to start checking it out this morning but I tried to start it this morning while warming up my truck. It’s 14 degrees and it fired up instantly and ran smoothly for fifteen minutes then I had to leave so I shut it off. It’s been below zero for a week in the morning here and yesterday it was -8 below wouldn’t start in morning, tried again in the afternoon it was 23 degrees still wouldn’t start. The other thing is I haven’t had the cover on it all week. I suppose the cover might keep the wind chill down. Next week I’ll check the valves and hopefully check the fuel pump but I’m thinking I should wait on that until below zero again to see what it’s doing when really cold.

Bought a 2025 last year. From day one it starts on the second try. I run ethanol feee gas.