What do you need to know. An excellent medium to light duty saw. Make sure it runs and idles. Start it up , warm it up a little and set it down. It should stay running. Shut it off and start it again. It should take 1 and only 1 pull. Pick it up by the starter handle, the rope should not start pulling out. This checks compression. Look at air filter, it should have NO holes. Look at bottom of saw. Some paint scratches and small bare spots is the sign of a low to moderately used saw. No paint means it has seen much use.
For a home user and firewood saw with a 16 inch bar, it is hard to beat. Parts are still in system.