Our verdict
The Kubota zero-turn that small landscape contractors actually run. Pro Kawasaki engine, commercial-grade hydro pumps, and the same deck weld quality as machines costing 50 per cent more. Diesel commercial buyers should look at the ZD series, everyone else gets the right balance of price and durability here.
Pros & cons
Pros
- Kawasaki FX691V, the pro-grade commercial V-twin
- Welded steel deck, not stamped, for daily use
- Hydro-Gear ZT-3400 transmissions, the same as commercial Ariens and Wright
- ROPS bar fitted as standard
Cons
- Side-discharge only, collector kit adds £900
- Petrol fuel cost on commercial routes
- No suspension seat as standard at this price
Full specs
| Type | Ride-on |
|---|---|
| Cut width | 122 cm |
| Engine / Power | Kawasaki FX691V V-twin petrol 22HP |
| Weight | 340 kg |
| Deck | Steel |
| Self-propelled | Yes |
| Rear roller | No |
| Mulching | Yes |
| Cutting heights | 6 positions |
| Bag capacity | — |
| Suited to lawn | Large |
| Noise level | 100 dB |
Buying second-hand
£3500-7000 used. Kawasaki FX hours under 800 are excellent, under 2000 acceptable. Hydro pumps are the standard wear point on any zero-turn, listen for whining under load. Deck-belt tension is operator-adjustable, a stretched belt is a £40 fix, not a deal-breaker.
Where to buy the Kubota Z421KW-3
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Repair-cost reference
UK 2026 ballpark prices for the parts you're most likely to need on this mower. OEM is dealer-genuine; aftermarket is what you'll find on eBay or generic small-engine suppliers. Use these to sense-check any quote and to negotiate on used buys.
| Part / job | OEM | Aftermarket |
|---|---|---|
|
Replacement 122cm blade
Annual sharpening is free; replace when bent or cracked.
|
£24–£32 | £8–£12 |
|
Oil filter
|
£18 | £9 |
|
Air filter + pre-cleaner
|
£35 | £18 |
|
Spark plugs (pair)
|
£18 | £9 |
|
Deck spindle bearing
Replace if blade vibrates or the deck whines under load.
|
£48 each | £22 each |
|
Transaxle service (gear oil change)
Hydrostatic units need fresh fluid every 200 hours.
|
£60 dealer | £15 DIY |
|
12V starter battery
Generic 12V 18Ah lawn-tractor battery — fits most ride-ons.
|
£45 | £28 |
Fair-offer calculator
Tell us about a specific used listing for the Kubota Z421KW-3 you're looking at. We'll compute a fair offer range from our used-market data and the condition signals you provide.
Calculations are guidance, not gospel. Used-market prices vary by region (Scotland is typically 10–15% cheaper than the South-East), season (October cheapest, March most expensive), and seller motivation.
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