Just purchased a 2008 29' Amberjack....

[falcor]

Just purchased a 2008 29' Amberjack. 400 hrs.   Looks like the risers are the original ( boat was sold in 2010 )  Can anyone tell me if the risers & manifold need to be replaced or just the risers?  Thanks.

According to paperwork, the rises were sent out to have them cleaned & tested in 2016

[wingless]

My guess is the boat has twin Mercruiser 5.7 Horizon engines w/ raw water cooled exhaust. Please identify / confirm the engines.

http://images0.boattrader.com/resize/1/11/4/6561104_0_290120181349_137.jpg?t=1268633

If the boat is operated in salt water, then the OEM Mercury parts are good for 3-5 years before they must be discarded. Aftermarket parts cost less and have a shorter service life.

The service life in fresh water will be longer.

The best option is to unbolt the elbows, clean off the gasket surface, then inspect for the SOLID wall thickness between the exhaust passage and the raw water passages.

The parts are discarded when the solid wall thickness has deteriorated to an insufficient thickness.

This inspection should be performed annually after the second year of the exhaust parts being put into service.

When required, replace the manifolds, risers and elbows together on both sides and both engines.

On my salt water 454 Horizon engines, I designed and installed a custom fresh water flush system to run fresh water, soapy water, then Salt Away after each use. Then I drain the parts bone dry, instead of the original design that had the bottom of my manifolds wet 24/7/365.

[falcor]

thanks for getting back to me. Does have 5.7 Mag MPI Horizon engines. Fresh water cooled with attachment for a hose for flushing. All the other engines I had worked on always had both manifold & risers saltwater cooled. These appear to have only the risers saltwater cooled

[wingless]

My suggestion is to always do the fresh water flush followed by Salt Away after every usage.

My suggestion is to do an annual removal / inspection of the risers and elbows for solid wall thickness after those parts are two years old.

[falcor]

Thanks for the advise