Grey 300D Outboard Motor Cover – 6 Sizes for 2–150 HP Engines

These grey outboard motor covers (Osculati 300D series) are designed to keep your engine’s powerhead dry, clean, and protected whether at the dock, during trailering, or in long-term storage. They are made from high-quality marine-grade textile material and come in several sizes to cover the full range from small portable outboards up to large offshore engines.

Material & Construction:

• The cover is constructed of 300 Denier polyester – a tough, woven fabric that offers an excellent balance of durability and flexibility. The interior side of the fabric has a polyurethane (PU) coating, which renders the cover fully waterproof. Rain or spray simply rolls off. The seams are well-stitched, and critical areas are likely double-stitched or reinforced to prevent leaking and to withstand strain.
• Sewn into the hem around the bottom opening is an elastic shock cord running all the way around. This elastic allows the cover to grip snugly under the engine’s cowling lip – you just slip the cover over the top of the engine and the elastic keeps it secure beneath the bottom edge of the cowl. Some sizes also include a drawstring and toggle to cinch the hem even tighter, which is especially handy to ensure it stays put during highway towing.
• The shape of the cover is tailored to the typical outboard cowling form – roughly rectangular with a taper, wider at the top (to accommodate the engine head) and narrowing towards the bottom. This provides a smooth, close fit with no excessive bagginess, which otherwise could flap in the wind.

Advantages of covering your outboard:

• Weather Protection: When your boat sits outside, the engine is exposed to UV rays – over time, the cowling’s paint can fade and plastic parts/gaskets can dry out and crack. With a cover, the motor is shielded from the sun. Also, rain and salt spray are kept off the engine’s exterior, which helps prevent small corrosion spots and keeps moisture out of the cowling (reducing the chance of water entering the engine’s air intake or electrical areas). Even for short periods of disuse, the cover keeps things like dust, bird droppings, and leaves away – all of which could stain or clog vents if left to accumulate.
• Extended Lifespan & Appearance: Using a cover regularly keeps your engine looking like new. After a few years, you’ll notice a stark difference – an engine that’s always covered maintains a glossy, unfaded finish, whereas an uncovered motor often turns chalky or dull from UV damage. For those who care about aesthetics or resale value, this is a big benefit.
• Protection During Transport: If you trailer your boat, especially over long distances, the cover shields the engine from road debris (grit, tiny stones, insects) that can smack into it at highway speeds. It also minimizes vibration of the cowling because a tight cover prevents wind from catching under the edges. Note: When trailering with the cover on, ensure the elastic hem is very secure and no part of the cover is flapping – a properly fitted cover should stay taut and not balloon at speed.
• Ease of Use: There are no zippers or complicated straps – it simply slips on like a cap over the engine. For small motors this takes seconds; for larger ones maybe a minute to adjust around the corners. Likewise, it comes off easily. This convenience means you’ll actually use it regularly (no excuse that it’s too much hassle), even for short periods between outings.

Sizes & Compatibility:
Osculati provides six size options, approximately as follows (with rough dimensions L×W×H of the cover and HP guidance):

1. Size S (~40×25×32 cm) – fits very small outboards around 2–4 HP (single-cylinder portables, often with carrying handles).
2. Size M (~48×27×35 cm) – fits 5–15 HP engines (small twin-cylinder portables).
3. Size L (~55×33×45 cm) – fits mid-sized engines ~15–30 HP (these have taller cowls requiring more height).
4. Size XL (~63×35×50 cm) – fits 30–60 HP range (typical mid-range outboards, often 2 or 3 cylinders in four-stroke, or older 2-stroke triples).
5. Size 2XL (~73×40×65 cm) – fits large outboards ~60–100 HP (including many 4-cylinder four-strokes or V4 two-strokes with relatively big, bulky cowlings).
6. Size 3XL (~75×45×75 cm) – fits very large outboards ~100–150 HP (including some V6 engines up to about 150–175 HP, depending on model/generation).

When selecting a size, use the HP rating of your motor or, better yet, measure the cowling’s length (front to back), width (side to side), and height (bottom to top). It’s generally better for the cover to be a little loose rather than too tight – the elastic will take up slack. For example, if you have a 100 HP engine that’s kind of between sizes, you might choose the 60–100 HP cover for a snugger fit, or go up to the 100–150 HP size if your engine is an older model with an unusually large cowling. The elastic can usually accommodate some variance.

Additional features: The grey color is neutral and practical – it doesn’t attract as much heat as a black cover would, and it doesn’t show dirt as readily as a white cover. It also blends nicely with most boat/motor color schemes. The 300D fabric is heavy enough to be durable but still light enough to fold up compactly – you can stow the cover in a small bag or under a seat when the engine is in use. Out of the package, it’s typically just the cover itself – there aren’t extra straps to fiddle with, keeping it simple.

Tips:

• The cover is meant for a non-running engine. Always remove it before starting or operating the motor! It’s not designed to stay on during engine use – that could lead to overheating or the cover blowing off.
• If your boat is in the water with the engine tilted down, ensure the cover’s hem isn’t sitting in the water (usually not an issue unless the boat is very small and engine low). While the material is waterproof, prolonged soaking isn’t ideal.
• For long-term storage (e.g., winter lay-up), it’s good practice to clean and dry the engine before covering. You might also mist some anti-corrosion spray under the cowling; the cover will help hold that protective coating in place by keeping out moisture.
• The cover can be cleaned by hand with mild soap and water if needed. Machine washing is not recommended as it could degrade the waterproof coating – but frankly, usually a rinse or wipe-down is all that’s needed.

In sum, the grey 300D outboard motor cover is an essential accessory for any boater who wants to extend the life and looks of their engine. For a minimal cost, it saves you from potential issues like a faded, cracked cowling or internal corrosion, and it keeps your outboard ready for action – dry and clean – whenever you are.