I just cleaned out and rebuilt my carburetor on my 3.5 HP Tecumseh and was wondering how to get the perfect idle tuning. It idles rough now and wants to move forward when I start it up and I have two screws with the needles on them. One is on the bottom of the carburetor's bowl and the other screw is on the other side of the choke. How much should I turn both of them to get a stable idle without it stalling and the bike jolting forward?