I've been watching these threads since '06.
Have ran a few though the years, Every one of them was screaming lean.
Snipped the tabs off and have been running 1-1/4 low 1-1/2 high.
The reason I see why Dolmar went to that extreme was all the toasted 5100s.
The EPA mandated they run within limits with "tamper proof" adjustments.
They ate crap on all the warranties, only because they made a saw that is good, and ran like a banshee. (of course it was set too lean)
Back in the day the 5100 was every ones baby.
And it is still a great saw. Why do you think they get their huevos busted so much?