When should a MerCruiser manifold be replaced?
You should get 5 years out of the E coated Mercruiser exhaust. Just be careful when inspecting because you can’t alway see a problem developing where the raw water side is going to leak in to the exhaust gas side so even if they still look good at 5 years you should replace them anyway.
How long do MerCruiser manifolds last?
OEM MerCruiser manifolds and riser elbows can last more than 5 years in salt water if properly cared for, but, every year over 5 years on a salt water application is a gamble with the life of your engine on the line.
How long do marine exhaust manifolds last?
Most experts suggest that a manifold will have a life expectancy of six to eight years. However, heavy use in saltwater can see this drop to as low as three years, while lightly used freshwater boats can get up to 20 years out of a manifold.
What is a dry joint exhaust manifold?
The term Dry Joint Exhaust refers to MerCruiser’s patented exhaust system which utilizes 2 coolant passages vs 4, between the manifold and riser that are separated outside of the exhaust gasket. The term Dry Joint Exhaust is primarily associated with the cast iron MerCruiser Exhaust Manifolds and Risers.
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.
What is marine wet exhaust?
A wet exhaust mixes seawater with the exhaust before it can be routed out of the boat. Injecting seawater into the exhaust can dramatically lower the temperature of exhaust run, which reduces risks of fire or being burned by an exhaust pipe.
What should you always do before starting an inboard engine?
If you have an inboard gasoline engine, you need to turn on the blower for four full minutes before starting your boat. This very important step is to remove any fumes that could be lingering in the bilge. All portable fuel tanks must be filled off of the boat.
Why do boats exhaust into the water?
Wet exhaust engines: Include most conventional outboard or stern-drive engines, which exhaust through a vent in the propeller. Use raw water from its surroundings to keep the engine cool, which flows in through the seacock, and is expelled through the exhaust.