My McCulloch Chainsaw (Power Mac 310) has so much compression that I am unable to start it using the pull starter cord. Without the Spark Plug the piston moves freely. Once the spark plug is inserted the starter cord is almost impossible to pull.
What is the remedy?

Ray Unser, June 2009

Removed spark plug and flooded cylinder with Breakfree and WD-40. Let soak for 24 hours cycling piston frequently with starter cord.
After soaking period, replaced spark plug and sprayed ether in Carburetor. Engine started on 3rd pull and continues to start on 2nd pull after numerous shutdowns (without use of ether as a starting fluid). Problem resolved

Ray Unser, June 2009