Mountfield S421R PD 16″ Petrol Roller Lawn Mower

Why buy the Mountfield S421R PD 16″ Petrol Roller Lawn Mower? Powered by a reliable 139cc STIGA ST 140 Autochoke petrol engine. Features a full-width rear roller for creating classic, professional lawn stripes. Self-propelled drive system makes mowing effortless, especially on inclines. A 41cm (approx. 16″) cutting width, ideal for small to medium-sized gardens. Large 55-litre grass collector with a ‘bag full’ indicator to reduce emptying trips. Centralised cutting height adjustment with 5 positions from 20mm to 70mm. Create Flawless Lawn Stripes For those who desire a quintessentially British striped lawn, the Mountfield S421R PD roller lawnmower is the perfect solution. At its core is a reliable and punchy 139cc STIGA ST 140 Autochoke engine, providing ample power to the 41cm cutting blade and the self-propelled rear-roller drive. This combination ensures a perfect finish and makes light work of lawns up to 1000m². Effortless Operation and Control The self-propelled drive system, engaged via a lever on the handlebar, propels the mower forward at a fixed speed of 4.1 km/h, removing the effort of pushing. This makes navigating gentle slopes and larger areas a breeze. The S421R PD features a robust steel chassis for durability and an ergonomic, soft-grip handlebar which is both adjustable and foldable for comfortable use and compact storage. The cutting height can be easily adjusted through 5 positions, ranging from 20mm to 70mm, using a single centralised lever, allowing you to achieve the exact look you want for your lawn. Efficient Collection and Build Quality Grass clippings are efficiently managed by the 55-litre hybrid grass collector. This canvas and hard-top bag is designed for optimal airflow and features a convenient ‘bag full’ indicator, letting you know precisely when it’s time to empty. The mower is built upon a robust steel deck, ensuring longevity and performance. The grooved wheels with ball bearings provide smooth travel across the turf, contributing to an even and clean cut every time. Your Authorised Mountfield Dealer When purchasing the Mountfield S421R PD, choosing an authorised UK dealer like Sims Garden Machinery provides significant advantages. With a century of experience, our focus is on providing long-term value, not just selling a box. Our trained sales staff are on hand to offer expert, impartial advice at our Stratford-upon-Avon showroom. For local customers, this lawnmower includes a complimentary Pre-Delivery Inspection (PDI) by our trained mechanics, ensuring it is built, fuelled, and tested before it leaves us. This service is paired with free local delivery and a comprehensive handover demonstration, so you can start mowing with confidence. This level of support guarantees your new mower is ready for peak performance from day one. Not sure which machine or part is right for you? Our team is here to help. Contact us today for expert advice. Technical Specification Power Power Source Petrol Power 2.2 kW Recommended Mowing Area 1000 ㎡ Engine Brand STIGA Engine Model ST 140 OHV Autochoke Powered by STIGA Displacement 139 cm³ Engine Rotation Speed 2900 rpm RPM Control Fixed rpm Starter Recoil Fuel Tank Capacity 0.75 l Engine Oil Tank Capacity 0.5 l Cutting System Cutting Method Collecting Cutting Width 41 cm Deck Material Steel Cutting Height Adjustment Centralized Cutting Height Positions 5 positions Cutting Height Range 20 – 70 mm Drive System Driving Self-propelled Traction Rear-roller drive Speed Forward 4.1 Km/h Equipment Collector Capacity 55 l Handlebar Type Ergonomic soft grip Wheels 180 mm / ROLLER grooved wheels on ball bearings Front Handle Yes (bumper) Adjustable Handlebar Yes Foldable Handlebar Yes Collector Type Hybrid with warn indicator Vibration and Noise Data Guaranteed Sound Power Level (LwA) 96 dB(A) Measured Sound Power Level 95 dB(A) Sound Pressure Level at Operator Ear 81.2 dB(A) Vibration Level Hand (m/s²) 7.5 Overall Dimensions Weight 32 kg Pack Weight 34.7 kg Product Length 1500 mm Product Width 490 mm Product Height 1120 mm Why buy from Sims Garden Machinery? Authorised main dealer We are authorised dealers for leading brands, meaning genuine parts, manufacturer-approved training, and warranty support you can rely on. Real people, real support No call centres. No ticket systems. Just a knowledgeable local team you can speak to when you need help. Expert advice — not pushy sales Our team are trained mechanics and product specialists, so you get honest, practical advice based on how you’ll actually use the machine. Established, independent family business We’re a long-standing independent dealer with deep roots in the local area — built on reputation, repeat customers, and word of mouth. Frequently Asked Questions Is the Mountfield S421R PD good for creating lawn stripes? Yes, absolutely. The S421R PD is specifically designed for this purpose. It features a full-width rear roller that flattens the grass blades as you mow, creating the classic, professional-looking stripes that are highly sought after in British gardens. What size lawn is this mower recommended for? With its 41cm (approx. 16″) cutting width and self-propelled drive, the Mountfield S421R PD is an excellent choice for small to medium-sized lawns, with the manufacturer recommending a maximum mowing area of up to 1000m². How is the cutting height adjusted on this mower? The cutting height is very easy to adjust. The mower uses a centralised system, which means a single lever adjusts all four wheels simultaneously. There are 5 different height positions available, ranging from a low 20mm up to 70mm, allowing you to easily adapt to different grass conditions. What type of fuel and oil does the STIGA engine require? The STIGA ST 140 engine is a 4-stroke engine and requires standard unleaded petrol. For engine oil, a high-quality SAE 30 or 10W-30 4-stroke engine oil is recommended to ensure optimal performance and lubrication. It is important to check the oil level on a flat surface before each use. 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