Small Engines (Lawn Mowers, etc.): lawn mower, briggs stratton, compression release

Question
I have a Poulan Pro 42 inch cut 18.5HP. when you try to start it it acts as if you have a dead battery. When you turn the key sometimes it turns slow for 1-1.5 turns sometimes it won't do anything. I have jumped it to the starter and get the same resolts at best.The clutch brake is set,battery is charged.The lawnmower has been doing this every since we got it but not as bad as now.You kept playing with the key and after a while it would start and when it did it would act like it was skipping for 10-15 min. under load.after that it would smooth out The moter is a Briggs & stratton INTEK 18.5HP ,OHV,AVS MODEL 31P777
TYPE 0299E1 CODE 041122ZD If you could give me any ideas on what is wrong with it i would greatly appreciate it.
by the way i have replaced the spark plug it made no difference.
thank you for your time and help
                           signed Kenny

Answer
Probably the valves need adjusting.  The compression release depends upon proper valve adjustment to function.  The following link will explain the function and the process for adjustment.  Let me know if you have any trouble.  Thanks, PK.

http://faqs.custhelp.com/cgi-bin/faqs.cfg/php/enduser/std_adp.php?p_faqid=3441&p...