Honestly just use regular gasoline and oil, drain the gas in autumn and run it dry and don’t worry the small stuff. These small engines are so cheap and consumable that they are not worth worry. Troy Built ain’t what it used to be, now bought out by the big boys. I keep thinking of replacing the B&S on my splitter and have considered it for the past ten years but never get around to it, now 30 years old and going strong except for occasional carb ($24) because I let it sit with gas. About ten years ago I did put in a new spark plug.
We owned a Briggs powered splitter but sold it when it got old.
Bought a 5.5 horse Honda powered TroyBuilt at a big box store. Just love it.
The Honda is easy to start, has low end grunt on big wood and is economical.
10W-30 fresh each fall. Drain the gas from the gas line.
There’s work to do next spring...