Small Engines (Lawn Mowers, etc.): snapper 2100HHB blower, exhaust port, muffler

Question
My blower starts and runs okay, however it does not have same cfm or hp it used to.  It only revs up to what seems like a fast idle.  I have made adjustments to the high/low screws, replaced spark plug and cleaned air filter.  Do you have any other suggestions, or is it simply wear on the engine which has lost the hp?

Thanks

Answer
 Hello Eric:

 Check the Exhaust Port and the Muffler and Spark Arrestor Screen for Blockage. The Exhaust Sounds like it is Restricted. The Spark Arrestor Screen is in the Muffler. Hope this Helps. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John