Cobra MX515SPBI 20″ Petrol Lawnmower

Why buy the Cobra MX515SPBI 20″ Petrol Lawnmower? Powerful and reliable 163cc Briggs & Stratton 675IS InStart engine Durable, corrosion-resistant cast aluminium deck Wide 51cm (20″) cutting width for efficient mowing of larger areas 5-speed self-propelled drive for complete control over mowing pace Versatile 3-in-1 functionality: collect, mulch, or side discharge Large 60-litre grass bag with a convenient ‘bag full’ indicator The Cobra MX515SPBI is a premium 4-wheeled petrol lawnmower designed for both discerning domestic gardeners and professional users who require robust performance and versatility. With its wide 51cm (20″) cutting width, it is ideally suited for maintaining medium to large-sized lawns efficiently. Briggs & Stratton InStart Engine At the core of the MX515SPBI is the Briggs & Stratton 675IS InStart engine. This powerful 163cc engine eliminates the need for a traditional recoil pull-start, offering effortless starting at the push of a button. The innovative InStart battery provides over 50 starts from a single full charge and can be quickly recharged from flat, ensuring the mower is always ready for work. Durable Aluminium Deck & 5-Speed Gearbox This mower is built to last, featuring a hard-wearing, cast aluminium deck. This premium construction offers superior durability, resistance to corrosion, and is easy to clean, promising a longer working life compared to standard steel decks. The self-propelled drive system is managed by a reliable 5-speed gearbox, giving the operator complete control. The speed can be adjusted from 3km/h to 4.2km/h, allowing for a slower pace in intricate areas and a faster speed for covering large, open spaces with ease. Versatile 3-in-1 Cutting System The Cobra MX515SPBI provides ultimate flexibility with its 3-in-1 collection system. For a pristine finish, the large 60-litre fabric grass bag collects clippings efficiently and features a ‘bag full’ indicator to prevent overfilling. For a natural lawn feed, the included mulch plug recycles clippings by cutting them finely and returning them to the soil. For overgrown or informal areas, the side discharge chute quickly disperses clippings without the need for collection, speeding up the mowing process. Designed for the User Every feature is designed for convenience and a superior cut. A single lever adjusts the cutting height through 7 stages, from a low 25mm to a high 75mm, making it suitable for various grass conditions. The handles feature a cam lock system, allowing them to be folded quickly for more compact storage or transportation. This combination of power, durability, and user-friendly features makes the Cobra MX515SPBI a standout choice in the walk-behind mower category. As an authorised UK dealer for Cobra, Sims Garden Machinery has been serving customers for over 100 years. All machinery purchased from us is fully assembled and prepared by our trained mechanics. For local customers, we offer a free pre-delivery inspection (PDI), personal delivery to your door, and a comprehensive handover demonstration from our trained sales staff, ensuring you can use your new mower confidently and safely. You can also view this machine at our Stratford-upon-Avon showroom, where our team is ready to assist. Not sure which machine or part is right for you? Our team is here to help. Contact us today for expert advice. Technical Specification Engine Briggs & Stratton 675IS InStart Displacement 163cc Starting System InStart Push-Button Drive Self Propelled, 5 Speed Speed 3km/h – 4.2km/h Cutting Width 51cm / 20″ Cutting Height 25 – 75mm / 7 Stages Collection System 3-in-1 (Collect, Mulch, Side Discharge) Grass Bag Capacity 60L Grass Bag Full Indicator Yes Folding Handles Yes, with Cam Lock Deck Material Aluminium Wheels 4 Wheeled Weight 38kg Domestic Warranty 2 Years 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 Frequently Asked Questions Who is the Cobra MX515SPBI lawnmower best suited for? The Cobra MX515SPBI is ideal for gardeners with medium to large-sized lawns who need a powerful, reliable, and versatile machine. Its durable aluminium deck makes it suitable for both demanding domestic use and light professional work. The 5-speed gearbox provides excellent control for properties with varied terrain or complex borders. What is the Briggs & Stratton InStart system? The InStart system is an innovative lithium-ion battery-powered starting mechanism. It replaces the traditional pull-cord with a simple push-button, making the mower incredibly easy to start. A fully charged battery can provide over 50 starts, and it recharges quickly, offering maximum convenience. What are the benefits of the 3-in-1 cutting system? The 3-in-1 system offers great flexibility. Collection provides the cleanest finish by gathering all clippings in the 60L bag. Mulching finely shreds the clippings and returns them to the lawn as a natural fertiliser. Side Discharge is perfect for longer grass or when you need to mow quickly without stopping to empty a bag. Is the aluminium deck a significant advantage? Yes, a cast aluminium deck is a premium feature. It is significantly more durable than a standard steel deck, is highly resistant to rust and corrosion, and doesn’t distort over time. This ensures a longer lifespan for the mower and helps maintain consistent cutting performance. User Manuals / Downloads View Cobra Brochure