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Model # 911170

Internet # 203436844

21 in. Classic Kohler XT8 Push Gas Walk-Behind Lawn Mower

This item has been discontinued.
The Home Depot no longer carries this specific product.

$529.00 /box



Model # 911170

Internet # 203436844

Walk your way to cutting perfection. Choose the Ariens 21 in. Classic Walk-Behind Push Lawn Mower and you can expect a professionally manicured result every time. The innovative cutting design features a stamped steel deck with a rolled under lip for added durability and maximum airflow providing you with excellent cutting results.

  • 4.5 HP/173cc Kohler XT-8 engine
  • 14 Gauge stamped steel deck
  • 6 cutting positions
  • Push drive system
  • 1 in. to 3-1/4 in. height of cut adjustment
  • 4 position adjustable handlebar
  • Includes mulch plug, side discharge cover and bag
  • High-lift blades to maximize bagging efficiency
  • 21 in. cutting width
  • Item usually ships in 7-10 business days
  • Delivered to your door mostly assembled, simply attach the handle using basic instructions
  • Home Depot Protection Plan:

    Home Depot Protection Plan

Info & Guides

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Assembled Depth (in.) 
39 in 
Assembled Height (in.) 
20 in 
Assembled Width (in.) 
24 in 
Blade Length (In.) 
21 in 
Mower Deck Width 
23 in 
Rear wheel size (in.) 
Size of Yard 
1/4 Acre or Less 
CA (CARB) Compliant 
CARB Compliant 
Cutting Options 
Cutting Width (in.) 
Engine Displacement (cc) 
Engine Make 
Adjustable Handlebar,Bagger,Foldable handle,Rust resistant deck,Tool-free adjustments 
Fuel Type 
Fuel tank capacity (gallons) 
Handle Material 
Engine oil 
Lawn Mower Type 
Walk Behind 
Manual Push Mower Type 
Maximum cutting height (in.) 
Minimum cutting height (in.) 
Mulching Capability 
Number of Blades 
Oil capacity (oz.) 
Product Weight (lb.) 
100 lb 
Recommended oil 
10 w 30 
Start Type 
Uneven with Obstacles 
Walk Behind Mower Type 
Manual Push 
Warranty / Certifications
Manufacturer Warranty 
3-year limited consumer 


Rated 3.8 out of 5 by 98 reviewers.
Rated 1.0 out of 5.0 junk I have never had such a piece of junk it's hard to start if it starts at all. I spend more time fighting with it than mowing the lawn. I give it one star and that's one to many. June 7, 2015
Rated 4.0 out of 5.0 by Very nice mower. I like the Ariens mower for several reasons. 1) the bagging is unbeatable, even in the rain, it will completely pack the catcher full - no clogs. 2) Starts every time the first time. 3) The Kohler motor, even though it is small in cubic inches, it has plenty of horsepower to handle tall grass and blow through it. May 22, 2013
Rated 1.0 out of 5.0 by My Ariens mower was junk, so I brought it back to the store After using my mower once a week for 3-4 months, it stopped working reliably. It would work well for 5-10 minutes, then not work again until it had cooled down completely. Having to mow your lawn in 5 or 6 shifts is ridiculous. Tried different gas, cleaning all the filters, new spark plug, nothing would help. Even when it did work, it had a horrible design. The self-propulsion is belt-driven, and the belt is exposed to all the grass clippings under the mower deck. Sounds like a joke that an engineering professor would tell his students in class. Anyway, I brought it back for store credit and I've been happy with the replacement (another brand) June 12, 2012
Rated 3.0 out of 5.0 by Commercial User Have bought 4 of these mowers. A good cut, fast speed on the ground, not to heavy. Problem is the bearings in the drive assembly don't last long. Pity as otherwise a great mower. Getting parts in the UK a problem. Approved dealers not much help. May 29, 2014
Rated 4.0 out of 5.0 by LM21 Hit a rock in lawn early last season, bent blade in half weak steel used in blade construction. Try to go back to Home Depot for new blade but they don't carry Arien replacement parts. Ariens dealer 50 km away. Found aftermarket blade at Canadian Tire now mower shake and vibrates. Motor shaft is not bent and I get blisters everytime I use it. Now used Sunday morning cut half the lawn in morning waited until after dinner went back to finish and lawn mower will not start at all. I think I would rather use the weed eater than the lawnmower to cut my grass. Overall strong engine wide cut width pleased with that but not much more. June 12, 2012
Rated 5.0 out of 5.0 by Works like a horse. Purchased my Ariens LM21 with the 149cc Kohler engine last year from Home Depot. I cut an acre and a half at least twice a week during the summer. Hasn't let me down yet. Change the oil, clean the air filter and a quick wash each time I'm done and next time around it always starts on the first pull. This lawnmower has been a great addition to my yard maintenance arsenal. My only minor complaint is that its a little hard to clean under the deck, and the design seems to really like to collect grass around the discharge areas and under the deck if its at all damp. It can make the mower a little heavy to push at times. June 12, 2012
Rated 4.0 out of 5.0 by Ariens model LM21 a good product after 6 years I purchased an Ariens LM21 with the swivel front wheel option 6 years ago. It has the 6.5hp Briggs & Stratton Quantum engine. It starts after priming it 7 times and one or two pulls time after time and year after year. The only time it does not start well is if you turn it off to take a break and try to re-crank while its hot. It may take 5 or six pulls to fire it up again. The only part thats broken is the left rear tire tread skin ahs torn apart due to rubbing against bed pavers etc. Just ordered anew one. This has been a very powerful and good mower. The most powerful I've owned, better than the Snapper I had. I would purchase another when this one goes out. Good mower. August 9, 2011
Rated 4.0 out of 5.0 by Reliable starts and easy to operate I have had this unit for 3 summers now. Have only done basic maintenance (oil changes, filter cleans & blade sharpening)(no spark plug replacement). To date the unit has been very reliable. My initial concern was the automatic choke which has proved to be reliable and provides single pull starting. I had previously owned mowers with Briggs engines. I do like the Kohler engine on this unit. I primarily use the mower as a mulching unit. It gets the job done as well or better than any other mulching mower I have previously owned. Although the unit doesn't have a throttle control I haven't found this to be an issue. The units speed preset is where it should be for maximum performance. June 12, 2012
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