A couple of months ago there was a thread on this group about adjusting carbs with air bleed. Someone mentioned that their adjustments were all over the map, and suggested drilling out the hole in extreme cases.
Well, I drilled out the hole on my OS MAX 25 a couple of weeks ago, and finally got to fly it today.
Wow.
Before the modification I had the air bleed screw all the way out, the idle was blubbery, it would stall if you idled it too slow for very long at all, and it'd really load up when you hit the throttle.
Now it'll idle all day slow enough that the plane won't roll on pavement, it comes right up to full power right now, and just generally flies better.
Granted, the mid range is still too rich, but I'm not complaining. The engine works much better now.
So whoever posted the suggestion -- thanks. It works, and my plane is much happier now.