More than 2100 buyers on Home Depots site recommend the Toro Recycler 20333. The most helpful reviewer found the powerful engine did an excellent job of chopping through foot-high grass and the rear wheel drive gave him power while turning. He also mentioned that he could almost jog with it. Another buyer notes that his Toro still runs well after three years of questionable maintenance. He does note a couple negatives: It is a bit louder than the Honda and if you go to fast the mulch is not fine enough.
Your Best Digs also recommends the Sun Joe mower but the reviewer also added a number of caveats. He found it will get the job done if you prefer to only bag and just have $100 to spend. However the clippings compartment filled up quickly for him. And the height adjuster felt flimsy and required adjustments on each wheel.
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.