Air cleaner cartridge (pleated paper)
Likely- 593260 — Toro 21321 (serial 400000000 and higher) — engine confirmed as Briggs & Stratton 550EX on Toro's own product specification page
Manufacturer chain: Toro's own product page states this model ships with the 550EX engine (Engine Brand: Briggs and Stratton. Engine Series/Name: "5.5 ft-lb Gross Torque* Briggs & Stratton® Ex 140cc".). That engine's air filter was independently verified against a Briggs & Stratton parts diagram in an earlier batch — see that engine's own catalog row for the diagram citation. The Briggs 550EX Series is confirmed as the 140cc OHV Ex-family engine on Briggs' own product pages.
Source: Toro product specification page — Toro 21321 — Specifications: Engine Brand: Briggs and Stratton. Engine Series/Name: "5.5 ft-lb Gross Torque* Briggs & Stratton® Ex 140cc".
Changed partway through production: Applies to serial numbers 400000000 and higher, which is the modern EXi-generation range Toro's own spec page and third-party catalogues agree on. Toro has also sold this model number with older serials (some as low as the 290000000s); those are a different, earlier engine generation and are NOT covered by this record.
Blade, 21 inch
Likely- 133-8182-03 — Toro 21321 (SN 400000000-415399999)
Part 13: BLADE-21IN. Note: this is a 21-inch blade family, distinct from the 22-inch Recyclers above — do not cross-fit.
Source: PartsTree OEM parts diagram — Toro 21321 Engine and Blade Assembly — Engine and Blade Assembly: Part 13: BLADE-21IN. Note: this is a 21-inch blade family, distinct from the 22-inch Recyclers above — do not cross-fit. — 133-8182-03.
Changed partway through production: Covers SN 400000000 through 415399999; a later 415400000-999999999 range exists for this model and was not checked.
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