Small Engines (Lawn Mowers, etc.): how to tune a carb ?, poulan 2150, mixture adjustments

Question
i have a poulan 2150 chainsaw and i cant get it to idle slow enough the chain keeps spinning at idle i have tried adjusting the throttle but no luck and adjusting the card doenst have much affect either .. so am i over looking something or can you give me an idea of how to get it back in tune i have read the manual and it recommends taking to a poulan dealer blah blah and give no tips on adjustment except that the carb has set limits you cant go past on adjusting .. any help will be greatly apreciated !!

thanks in advance  

Answer
The side by side screws are the low and high speed mixture adjustments. The one closest to the cylinder is the low speed. Both should be set at 1 1/2 turns out from lightly seated as a starting point. From there, start it up and hold the throttle wide open. Turn the high speed screw in until max RPM is reached (do this quickly), from there open the screw 1/4 turn. Then you need to adjust the low speed (either open or closed) until it is open just enough that there is no bog from idle when you open the throttle quickly. The third screw is the idle speed adjustment.  The plastic limit caps on the mixture screws can usually be removed by grabbing with vise-grips near the end and pulling straight off to accomodate proper adjustment.  Hope this helps.