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manifold/riser lifetime-gctid378588

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    manifold/riser lifetime-gctid378588

    A month or so back I posted about replacing my manifolds/risers/spacers on my 5.7 mercruiser gas engines. Most of the feed back I received said at 10 years old I was pushing my luck.

    I have the old ones off and the new ones (sierra) on. The old ones look to be in good condition with no obvious signs of rust or wear (I do boat in salt water). Perhaps the fresh water flush after almost every use helped. The "meat area" where the gasket seals to the block looked unchanged/

    I went ahead and changed them out thinking that most areas are not visible and for peace of mind. I think I will take a baseline temp while running at numerous spots on the new gear with a hand held remote temp gauge from Harbor Freight. With some baseline temp reading I will then monitor periodically for signs of hot spots.

    Others have said that their gear looked very rusty after less years than mine so go figure.


    The biggest issue is not the manifolds themselves but the riser/manifold gaskets. Generally you should change them and inspect the risers every 3 years or maybe 5 if flushed religiously. AND use the Merc graphite gaskets.

    cheers, Gary