Mercruiser Exhaust Riser Kits

What is an exhaust riser? Exhaust manifolds and risers are large metal castings that carry hot exhaust gases away from the engine on inboard engines.

Sometimes the riser slopes down from the end of the manifold, if the engine sits high enough above the waterline, in which case it’s often called an elbow. All marine inboard engines have exhaust risers. The exhaust riser has two functions: (1) to keep water from backing up into the engine through the exhaust piping and, (2) it serves as the device that introduces cooling water into the exhaust exit piping system. Exhaust manifolds and risers are large metal castings that carry hot exhaust gases away from the engine on inboard engines. All V-8 and V-6 engines, for instance, have a separate exhaust manifold along the side of each cylinder bank. Marine engine exhaust riser is an important part of any marine engine exhaust system, whether big or small. MerCruiser decided that the overall height of the exhaust riser should be raised to meet the overall maximum height of the engine. Mercruiser, for example, has a wonderful reputation for risers that sometimes don't last a year. On average, in saltwater use, good risers last about 4-5 years. At 4 years, you should start worrying about them. Mercruiser 4.2 V6 riser. One common way to tell that a riser is going bad is to check to see if you notice rust stains coming from the riser-manifold joint. If you do see the rust stains, then this is a sign that the gasket is failing. In order to inspect things better, you should drain the water from your risers and manifolds. The exhaust riser has two functions: (1) to keep water from backing up into the engine through the exhaust piping and, (2) it serves as the device that introduces cooling water into the exhaust exit piping system. Wet joint manifolds and risers need the gasket replaced every second year, and typically don't last as long, often failing at the gasket surfaces. Mercruiser wet joint manifolds should be superseded/upgraded to the newer dry joint style, when due for replacement.