Small Engine Troubleshooting Problems? Ask a Mechanic Now.
When did saw last run? Was spark plug showing any carbon buildup? Engine can get hard to pull if the cylinder gets carbon buildup in it, increasing the compression.
Find a good carburetor cleaner , that will dissolve carbon, and remove the spark plug, spray cylinder down with the cleaner and let it sit, then do it again, and with spark plug removed ,spin the engine until you get all the cleaner out. Re-install the spark plug and try it.