How often should risers and manifolds be replaced?
The general consensus on raw water-cooled manifolds and risers is that they will last upwards of (6-8) years. Keep in mind that most if not all engine manufacturers do not put out a service bulletin on how long these maintenance items will last.
How long do Mercruiser risers last?
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.
How long do Mercruiser manifolds last?
Most experts suggest that a manifold will have a life expectancy of six to eight years.
How hot should exhaust risers get?
The exhaust manifolds on the port (regular rotation) engine run around 100 deg on the manifolds and 110 deg on the riser. The starboard (reverse rotation) manifolds run around 110 deg on the manifolds, but the risers get up around 180 deg when running at speed.
How do I know if my risers are bad?
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.
What are the signs of a bad exhaust manifold?
5 Symptoms of an Exhaust Manifold Leak
- Loud Engine Noise. The first and most common sign of any exhaust issue is loud engine noise.
- Poor Fuel Economy. Reduced gas mileage is another symptom of an exhaust manifold leak.
- Loss of Acceleration.
- Burning Smell from the Engine Bay.
- Exhaust Fumes in the Cabin.
How do manifolds and risers work?
Exhaust manifolds and risers are large metal castings that carry hot exhaust gases away from the engine on inboard engines. At the aft end of the riser, water from the water jacket combines with and cools the hot exhaust gases before continuing out the exhaust overboard discharge.
How do you clean marine risers?
One popular method to help clean up an old, dirty exhaust manifold is using an acid bath. Acid bath – An acid bath should be able to remove many of the problems that are present in your marine exhaust manifold. This is also very simple because it is a passive cleaning method that you can take advantage of.
What kind of riser does a Mercruiser have?
Aluminum Mercruiser style 4″ riser. This riser accepts a 4″ exhaust hose at a 7 degree angle. Replaces: Mercruiser 44354A3, 8079141, 807988.
What kind of exhaust riser does a Penta have?
Volvo Penta style 4″ center rise Exhaust Riser. Replacement for Volvo models: AQ & BB 200, 205, 231, 225, 260, 271, 290, 311, 500, 501, 570, 571 & 572. Replaces: Volvo 855384-4 and Sierra 18-1935-1. Volvo Penta style 4″ center rise Exhaust Riser. 1993 and Later Applications. Replaces: Volvo 3857723. Dry Joint Mercruiser style 4″ riser.
What kind of exhaust manifold does an iron MerCruiser use?
Iron Mercruiser Style 3.0L Exhaust Manifold for 1992 and newer applications. Will fit all 3.0L LX models. Complete with all mounting hardware. Replaces: Mercruiser 806867A 12, Osco 9798, and GLM 51214.