Small Engines (Lawn Mowers, etc.): Mcculloch power mac 310 carburetor adjustments, chainsaws, power mac

Question
I have 2 power mac 310 chainsaws that will not start. I believe that the hi/lo and idle settings need to be reset but I don't know how far to turn the needles in or out. Can you please help me. I do have an old owners manual but there is nothing in there regarding these settings. Thanks.......

Answer
Hi Brian,

First, check for spark.

The high speed mixture screw is initially set at 1 & 1/2 turns out.  Then adjust it to give good acceleration and top speed, while not closing the screw more than you need to.  The low speed mixture screw is set at 3/4 of a turn out.  Adjust that, to give a smooth idle.  The 3rd screw, the idle speed screw, is set to give a low idle speed without stalling.  

If no change, try starting after squirting fuel or starting fluid into the carb's air intake.

Let me know what you find.
Michael