JPrc is right. My QS106 did the same thing. Its usually the Hi end needle. My engine would not lean out to clean up the mid range till at least 10 gallons. It also had a "very slight" hi speed stumble. If I tried to lean this situation it would start to loose transition. After it gets broken in it'll let you adjust this out. Its a very slight adjustment as the needles are sensitive, it'll be the Hi end needle, keep flying it a tad Hi end rich a lot, it'll like it and it won't hurt a thing, give it time it'll come around.
when it does you'll really appreciate the power these 106's have...My engine took I figure 15 gallons to settle in, its awesome power....