Take note of rsieminski's comment: "Never run it slobbering rich. The metal will not come up to operating temp this way, the sleeve will not expand all the way, the sleeve will wear in at the cooler temp, and when you do externally run at a leaned out 2 stroke hot setting, it'll never produce the power it was capable of"

I have a 46fx that is between 500 and 1000 rpm short of where I am pretty certain it should be. The best explanation I've come up with so far is the break it. I think the engines first couple of runs were way too rich. I recall trying to be very careful not to let it get too hot, thinking that that would be harmful.

rsieminski - that is the most succinct, zero hand waving, statement I've read yet about engine break in and what it really accomplishes. Now, I think I too get it.