Small Engines (Lawn Mowers, etc.): briggs stratton 6.75 no power, brigg and stratton, briggs stratton

Question
Hi
I have a 2001 model Sears self propelled lawnmower with a 6.75 Brigg and Stratton engine.  Last year, I hit a root with it which bent the shaft.  I took it to amechanic who straightened it out but ever since the engine has little power.  Also, it's harder to start, although not terribly hard, since this happened.  Otherwise, it runs fine but cannot cut thick patchy grass.  It's a mulcher mower, but even taking it off mulch by opening the discharge does not seem to help.  I asked the mechanice if it has compression and the mechanic said you cannot do a compression test on these since they decompress to start.  It doesn't burn oil so I am hesitant to think it needs rings.  Any advice would be much appreciated.
Thanks
George

Answer
 Hello Walter:

 Im Assuming the Mechanic Changed the Flywheel Key.  The Flywheel Key is the Timing for most Small Engines. When you Bent the Crankshaft, Im Sure the Key was Damaged. The Hard to Start is a very Good Indication of this. Forget the Rings. They are OK. If the Mower Started doing this Right After Repaired then its the Key; if it Started After sitting all Winter. It could be the Carb needs Rebuilding.

 Good Luck

 Respectfully

 John