Add height and hose clearance to inboard exhaust systems. If combatting exhaust back-flow or clearance issues, a spacer can make a big difference. Sierra spacers provide the extra height to exhaust elbows and help prevent water from traveling back into the riser when throttling down. Installation of a spacer can also provide added clearance for exhaust hose routing. Engineered to be compatible with Crusader and other marine engine applications using Osco manifolds, these spacers feature CNC machined mating surfaces to eliminate additional preparation to establish a proper seal. Sierra uses special casting techniques to create risers with uniform wall thickness and leak tests each spacer prior to paint to ensure quality. For a solution to complex exhaust issues, look to Sierra elbow spacers. Key Features Engineered to meet or exceed OEM specifications Adds height to exhaust elbow to prevent back-flow issues or add exhaust hose clearance Includes drain and port plugs Backed by SeaStar SolutionsLimited Two-Year Warranty 18-1984 Application Guide ApplicationOEM Part NumberBarrCR 20 98128Crusader98128GLM52090Mallory9-40430Osco8128The Sierra Engine Parts SelectorIn addition to riser extensions, we offer a wide variety of other engine parts manufactured by Sierra. To see if we have the part you need, see ourEngine Parts Selector, where you can search by engine make, serial number and model or year of manufacture.