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MOUNTFIELD S421HP Petrol Lawn Mower

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MOUNTFIELD S421HP Petrol Lawn Mower
MOUNTFIELD S421HP Petrol Lawn MowerMOUNTFIELD S421HP Petrol Lawn MowerMOUNTFIELD S421HP Petrol Lawn Mower
MOUNTFIELD S421HP Petrol Lawn MowerMOUNTFIELD S421HP Petrol Lawn MowerMOUNTFIELD S421HP Petrol Lawn Mower
Our Price:  £239.00
List Price:  £279.00
Saving Of:  14%
(Inc. 20% VAT)(£199.17 Exc. VAT)


Out of Stock. Delivery estimated 14-21 days


  (1 Review)

SPECIAL OFFER:  A free Oil SAE30 for 4 stroke machinery 1 litre is available when you order 1 item or more of selected products.

A quality Mountfield-powered lawn mower.

A hand-propelled machine, you will enjoy total control of speed and direction with the S421HP. 

Easy to start with a powerful engine

Powered by a Mountfield ST140  engine with a recoil rope start system, starting this machine is very easy.

Adaptable & versatile cutting performance

This machine features the 4 in 1 cutting system that allows you to mulch, collect, rear or side discharge. A large 60 litre grass collector allows the operator to mow for longer periods of time, without having to stop and empty the grass bag. The grass bag is easy to remove, empty and refit. The mulch feature recycles the grass clippings back into the lawn, saving you time and effort emptying. The grass clippings feed the soil and provide extra nutrients. The rear discharge feature allows grass cuttings to be discharged at the rear of the mower.

Perfect for small to medium sized lawns

The S421HP has 6 different heights of cut from 22mm to 65mm. This can be changed by a single lever, found on the side on the machine. The cutting width is 41 cm / 16 inches, making this an ideal mower for small to medium sized lawns (20m x 20m).


This machine comes with a conditional 5 year warranty.


  • Engine brand: Mountfield
  • Engine type: ST140 OHV Autochoke
  • Engine capacity: 139 cc
  • Net power output: 2.20kW @ 2900 rpm
  • Starting method: recoil
  • Drive: hand propelled
  • Cutting width: 41 cm/ 16 inch 
  • Cutting heights: 25-65 mm (6 positions)
  • Cutting height adjustment: single lever
  • Roller: no
  • Collecting: yes
  • Mulching: yes
  • Collector: canvas with hard top 60 litres
  • Chassis: steel
  • Fuel tank capacity: 0.75 litres
  • Lawn size:​ 20 m x 20 m
  • Safety features: operator presence control
  • Wheels: front 200 mm rear 200 mm 
  • Warranty: 5 years (Terms and Conditions apply)
  • dB(A) rating vibration level: 95
  • Weight: 24 kg

Power Source:  Petrol
Cutting Width:  41 cm
Important:  PLEASE NOTE: Lawn Mowers are delivered drained of their fuel and oil. Please ensure you fill them with the appropriate amount of fuel and oil before first use to avoid damaging your machine. Always refer to the operating manual.

Part Number:  S421HP
SKU: M5-S421HP

Why choose us?

Garden Machinery Direct is a family run business with over 40 years experience in selling and servicing garden equipment. We're one of the biggest garden machinery retailers in the UK. Based in the Midlands, we're well placed to deliver products across the UK - though we do deliver internationally. We are main agents for all the biggest garden machinery brands, and have fantastic working relationships with world leading manufacturers.

Our goal is to offer customers top of the range garden machinery at discount prices, delivered direct to your door. Our friendly and professional staff are available by telephone or email to give expert advice on the equipment most suited to your needs or to answer any queries you may have. We also operate an efficient spare parts service, utilising the latest computer link-ups direct to manufacturers stocks.

All of the garden machinery we sell carries a manufacturers guarantee, supported by a nationwide network of authorised service dealers.

At Garden Machinery Direct we offer our customers the best deals and even better service.

Please feel free to contact us if you have any questions.

Average Rating (1 Review):  
Write a Review and share your opinions!

MOUNTFIELD S421HP Petrol Lawn Mower
Tuesday, 30 June 2020  | 



This review has not been appraised.

  • All machinery is tested by the manufacturer's trained technicians
  • When carrying out servicing and repairs, only genuine Mountfield parts & spares are used to ensure quality

View the Mountfield brochure for more information.

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