To clean it first start with a cool engine. If your mower has a fuel valve switch it off. If you can disconnect the spark plug too. Next use a leaf blower to blast away any old dirt and major debris. Now gently lay the mower on its side fuel cap facing up. Try to get rid of any junk on the mowers underside as well.
There is something Zen about spending an hour or two each week pushing the mower around the yard on a sunny day. The drone of the motor drowns out your thoughts as you work on a task with a clearly defined objective: Making your lawn look its best. Of course the deciding factor between an almost meditative experience and one filled with frustration is often the quality of the lawn mower you have.
The Sun Joe MJ104E has more than 1250 five-star reviews on Amazon. Buyer Jim has had his Mow Joe for more than a year and left it in the weather and abused it otherwise. He is happy with how it has performed. He cautions against buying the 16-gauge extension cord recommended by Amazon. Instead choose 12 gauge for 100 feet or more and 14 gauge for under 100 feet.