Yamaha HPDI 3.1L Outboard Engine Cover MAR-MTRCV-11-20. Cowling Cover Super heavy-duty protection for your Yamaha outboard’s cowling. Constructed of ultra-durable Sur Last solution dyed polyester fabric for the ultimate protection against fading and the elements, this non-abrasive, water resistant cover is resistant to UV, mildew and mold. The cover has a soft fabric inner liner for added paint protection, and screened on factory logos for unmatched style. Includes a snap-buckle strap and stretch cord for a snug fit.