www.iFourWinns.com

Hello,

I am experiencing an engine alarm when I take my boat up to 4000 RPM, temperature and oil pressure are normal on the gauges. I am thinking that the exhaust manifold sensor is causing the alarm. Is this a sign that risers/manifold are in need of replacement? The boat is a 2004 with 550 hours, the first three years were probably spent in fresh water. This is my sixth season of using it in the brackish waters of the upper Chesapeake Bay.

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2004 Vista 298
Twin 5.7L Volvo Penta GXi-E

Six seasons in salt/brackish I'd say for sure check em, if you have an IR heat gun check the temps, if they are hotter than about 150 after running on plane then they are probably starting to clog. Do you see any rust stains around the joint between the riser and manifold? If so thats also a good sign they need to be replaced because if you see signs of leaking on the outside, it can be leaking on the inside into the exhaust gas passage and that can cause water to leak into a cylinder.

When I took mine off at 5.5 seasons in salt to trouble shoot a running hot issue, one of the 4 outlets was completely clogged in one riser, the other was OK. But the running hot was really more due to low raw water flow that was being caused by barnacle growth in the water intakes, I now rod out those intakes once a month during the season.

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88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II