Yard Machines Garden Tiller Model 21AA405C500

Locating Your Model and Serial Numbers

The model and serial numbers are essential to find correct MTD® genuine factory replacement part numbers for your outdoor power equipment. Once you know these numbers, you can use either the illustrated parts look-up tool or the operator's manual download to easily search for the correct part numbers needed.

What should my model and serial number look like?

MTD's current (1997 and later) model and serial numbers are generally 11 characters in length. A character could be a number, dash or a letter. If 0 represented all numbers and/or dashes and X represented all letters, the model and serial numbers should appear as follows: 00XX000X000.

These are made of both letters and numbers, and typically look like this: 11AA111A111.

Where do I find the model and serial number tags?

Identification tags are located in areas unlikely to need replacement - even after years of use. For most of our power equipment, these tags are approximately 2" x 3" in size. They also have the MTD product's name, address and customer service phone number listed across the bottom.

Walk-Behind Mowers

Walk-behind model and serial number plate is located on the rear left side of the deck.

Model number will begin with 11 or 12

Riding Mowers

Riding mower model and serial number plate is located on the underside of the seat.

Model number will begin with 13 or 14

Tillers

Tiller model and serial number plate is located on the tine housing.

Model number will begin with 21

Two-Stage Snow Throwers

Two-stage snow thrower model and serial number plate is located on the frame cover, between the wheels.

Model number will begin with 31

Single-Stage Snow Throwers

Single-stage snow thrower model and serial plate is located on the units frame, near the belt cover.

Model number will begin with 31

String Trimmers

String trimmers have a small model and serial number sticker located on the units starter housing.

Model number will begin with 41 or 42

Chipper-Shredder-Vacuum

Chipper-shredder-vacuum model and serial number plate is found on the rear frame of the unit.

Model number will begin with 24

Leaf Blowers

Leaf blowers have a small model and serial number sticker located on or around the starter recoil assembly.

Model number will begin with 41 or 42

Edgers

Edger model and serial number plate is located on the rear frame of the unit.

Model number will begin with 25

Cultivators

Cultivators have a small model and serial number sticker located on the engine housing.

Model number will begin with 21

Chipper-Shredders

Chipper shredder model and serial number plate is located on the frame, below the chute.

Model number will begin with 24

Trimmer-Plus Attachments

Trimmer-plus attachments have a small model and serial number sticker located on the shaft of the unit.

Model number will begin with 41

How do I determine my product model number and/or serial number if the tag is missing or illegible?

If a product identification tag has been rendered illegible, or the numbers are not valid within our online support systems, it will be necessary to call in and speak directly with a Technical Support Agent for assistance in properly identifying these products.

Our Technical Support Department staff may be reached at 1-800-668-1238, Monday thru Friday from 8:00 a.m. to 5:00 p.m. EST. The technicians there will ask you a number of questions while researching our historical manufacturing archives in an effort to determine the model number and manufacturing data of the product. This research can often be a daunting task and may even involve submission of photographs or measurement of particular parts that will identify a production series.

We cannot complete this identification process over the Internet because of its complex nature and the need for direct conversation while researching.

Once the model number and manufacturing data are properly identified, we suggest writing the number in the Owner's Manual so it is readily available. You could also write it on the product with an indelible marker or an engraving tool.