Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I'm glad I found this site. Looks like there are a lot of knowledgeable folks here.

I have an Airens 924 - 3 years old. It is running a bit rough - sometimes dies on me, but always starts back up. I'd like to learn to do the maintenance on this machine myself, but I'm fairly new to all of this. (I've changed the oil each year and put air in the tires.) Today I took of the cover to the carburetor and sprayed all around with carburetor cleaner. I wanted to take off the spark plug and clean it or replace it, but the socket I have for spark plugs is too small. Is there a special socket for this? I also wanted to grease the fittings. I went to Home Depot to get Stens Mix Hi-Temp grease, but they didn't have it. Would I get this in an auto parts store? Or Sears? Is there any other general maintenance I should do?  Any help is appreciated.