If you know the factory settings you can close them and then screw them back out to factry settings, and then lean in in small increments from there. LSN seem to always be flush but I can't say that is an absolute. Someone else here may know for sure.
So, for example - the traxxas 2.5 has a HSN setting of 4 turns out from lean straight out of the box used to get the car at least started in most situations so that you can break it in. Then you lean in in 1/16 turn increments and make a few passes then do it again, and again until you feel the optimal performance - then it's sometimes suggested by some to richen slightly from peak settings to help the engine last that much longer.
Eventhough you have a different engine (I am assuming) the guidelines are similar for any engine.
Try
http://www.traxxas.com/support/pub/t...ctory_settings
For an overview in general tuning. FOLLOW YOUR CAR'S SETTINGS!!!!! but the ideas are the same in most cases.
Hope this helps - good luck!