Small Engines (Lawn Mowers, etc.): possible 32cc 16 McCollough chainsaw ring replacement, testing tools, exhaust system

Question
I own a 9 yr old lightly used chainsaw described above.It will not start hot. Cold compression is 140 and hot compression is 118lbs.I believe a rebuild is in order. Are replacement rings and required gaskets available? Is rebuilding this unit cost effective?

Answer
Parts are difficult if not impossible to find.  I do not think they are worth repairing.

Have you check the exhaust system (muffler) for restrictions?

Do you have access or are you familar with leakdown testing tools?  
It is possible that you may have a leaking gasket or seal.

Let me know.
Eric