Walk-behind mower · Ariens LM21S / LM21SW

Ariens 911533 and 911534 parts: blades and drive belt

Checked October 2, 2026 · From the manufacturer's operator's manual and parts list

  • 21 in deck

Fits 911533 (21 in deck) and 911534 (21 in deck).

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Parts for the Ariens 911533 and 911534

PartNumber and size
Blade Ariens 01137000 Qty 1 Search Amazon for 01137000
Drive belt Ariens 07217100 Search Amazon for 07217100
Mulch plug Ariens 71102700 Search Amazon for 71102700

Checked October 2, 2026 · 5 sources

Maintenance schedule
  • After first five (5) hours of operation. Then change oil after every 25 hours of operation.
    • Change engine crankcase oil
  • Every 100 hours of operation or each year
    • Replace spark plug
  • Every 100 hours of operation or yearly (more often if conditions require)
    • Remove blower housing and clean cooling fins

As printed in the operator's manual, form 01250000C.

Where's my model number?
MODEL NO. 911533 SERIAL NO.

Serial number label on the frame of the unit (manual Figures 1 to 3); the model and serial numbers are also on the product registration form.

Where these numbers come from (5 sources)

Every part number above is printed in at least two of these. Checked October 2, 2026. How we check parts.

  • Operator's manual 01250000C · Ariens Company · 4/05
    Details

    Walk Behind Lawn Mower Owner/Operator Manual, models 911086 LM21, 911102 LM21SCH, 911330 LM21SW, 911396 Pro21SW, 911514 LM21S, 911525 LM21SW, 911531 LM21S, 911532 LM21, 911533 LM21S, 911534 LM21SW (Service Parts page 26; Specifications page 27; Maintenance pages 17-18). Text read from the manuals.plus mirror of the same form (https://manuals.plus/m/244c9340712c07308bbc1476c6c6b5e0d3fda538ead0d8203ed2eb768c1c625f). (used for machine and part numbers)

  • Parts list · PartsTree (dealer copy of Ariens IPL) · IPL edition whose model notes list 911086, 102, 330, 396, 514, 525, 531, 532, 533, 534 (the same set as manual 01250000C)
    Details

    Ariens 911533 (LM21S) SN 000734 & above: Engine, Blade And Belt (item 1 07217100 'V-BELT, 3L-COGGED'; item 12 01137000 '21" MOWER BLADE' for 911086, 102, 514, 525, 531, 533, 534) and Mower Pan And Bag (item 13 71102700 'MULCH MASTER MULCHER ACCESSORY') (used for machine and part numbers)

  • Parts list · PartsTree (dealer copy of Ariens IPL)
    Details

    Ariens 911533 (LM21S) SN 000734 & above: Mower Pan And Bag diagram (item 13 71102700, no model restriction) (used for machine and part numbers)

  • Parts list · PartsTree (dealer copy of Ariens IPL) · IPL edition whose model notes list 911086, 102, 330, 396, 514, 525, 531, 532, 533, 534 (the same set as manual 01250000C)
    Details

    Ariens 911534 (LM21SW) SN 001009 & above: Engine, Blade And Belt (item 1 07217100 'V-BELT, 3L-COGGED'; item 12 01137000 '21" MOWER BLADE' for 911086, 102, 514, 525, 531, 533, 534) and Mower Pan And Bag (item 13 71102700 'MULCH MASTER MULCHER ACCESSORY') (used for machine and part numbers)

  • Parts list · PartsTree (dealer copy of Ariens IPL)
    Details

    Ariens 911534 (LM21SW) SN 001009 & above: Mower Pan And Bag diagram (item 13 71102700, no model restriction) (used for machine and part numbers)