I started to type that earlier and stopped halfway through.
I have a Grizzly600 and it has been a problem with mine.....It would run a little better than just when choke was on...but anytime you gave it throttle it would die.
Problem ended up being too much oil in the crankcase...causing it to "blow-by" and saturate the air filter with oil...not letting air get through.
I had to leave the oil level at the lower part of the site glass window to keep it from doing it.
Maybe not the same...but I see what you are sayin.