Another way to find a LS needle that is on the verge of being too lean is to just fly the plane around the traffic pattern a few times. You can usually hear it lean out some. Maybe pull up vertical and give it the throttle and listen. If it gets set the proper way on the ground and passes the fly test then it's set, but flying will throw some real life variables at the engine that you need to listen for.
That comment about the 125 being an odd ball Saito is dead on the money, imo.