Most common mix is 50:1 on the fuel.

I was referring to air:fuel, as it were.

It's 22 years old; if I didn't know to run it 40:1, we wouldn't be having this discussion.

Today I used it. 12 primer pushes, 10 pulls, 10 more primer pushes, 7 more pulls, starts on 8 (20th) pull, stutters on full choke, won't idle on 1/2 choke, toggle between the two to keep it running. Stalls. Full choke, 6 primer pushes, 4 pulls, starts on 5th. Stutters on full choke, runs on 1/2 choke for 30 sec, choke off, runs, stutters, 1/2 choke, stutters after 20 sec, stalls. 3 primer pushes, starts on 2nd pull, full choke (yes full choke) rotate 90 degrees around shaft axis, idle picks up and steadies because I sank the fuel filter on the side of the tank that is now down. Run 20 sec, doesn't stall, dare not touch the throttle, hold at 90 degrees for 5 min while I trim. Off switch making contact today, use it to turn off.

So you see, it's a bit more complex than they designed it, so semi normal operation is sought.