that’s one for Brian or Jimbo that build those things. I know in the clones and predators we use 5w20 but I always thought Briggs wanted a thicker oil used.
I'd recommend the Briggs 4T oil as well.
Mobil 1 is ok. 5-20W would be fine, or even a straight 20W.
Now, it is VERY important that whatever oil you choose, that you stay with it.
There are MANY oils that are not compatible with one another and can quickly cause catastrophic failure.
If you have a used engine currently, find out exactly what oil was used in it previously, and either commit to that oil, or thoroughly flush the crankcase out with mineral spirits, dry, and cycle through a couple short interval oil changes of your new oil choice.
Briggs 4T, no question. Oil is cheap at any price....DON'T skimp!!! And change it often. Like after each event, at least!
Engines are expensive, oil's cheap!