Small Engines (Lawn Mowers, etc.): chainsaw, fuel mixture, exhaust ports

Question
Poulan 260 pro sat out in rain several days. Mixed oil/fuel ratio wrong. Still it worked,ish. Fixed some problems but slowly kept getting worse. Removed limiters on screws to get it running better and did for a while. Then it started getting worse again. Threw out bad fuel and corrected that. Got new spark plug. Checked exhaust ports. Fiddled with mixture screws for hours. I can get it to run well, but it has no real power. Set the chain on a log with it's own weight and it bogs down. It will cut, but you can't put any weight on it. Also, it spits back through carb into filter. Can you help? Ben

Answer
 Hello Ben:

 Assuming the Muffler and Spark Arrestor Screen are Also Carbon Free; What is the Compression? Set Both Fuel Mixture Screws to 1 1/2 Turns Out from Seat. Then Start the Engine and Hold the Throttle Full Open. Turn the High Mixture Screw IN Until the Engine Revs Properly. Set the Low Mixture Screw So there is No Hesitation when going from Idle to Full Throttle. Then Set the Idle. If the Saw has No Power when Cutting, then Turn the High Mixture Screw 1/4 Turn IN Until the Power Returns. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John