www.iFourWinns.com

I believe that the owners manuals and parts catalog will identify the thermostat as 175 deg F. The boat engine should approach that temp. It may take a little longer in cold water, but in 60 + deg water the temp should come up to between at least 1/4 to half scale on the gauge.

On mine mid scale is 175. It normally runs around 165-170.

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Surface Interval: A scuba diving term for that time between dives to relax and prepare for life's next great adventure.

Current boat: '02 FW 268 Vista
Previous boat: '95 FW 190 Horizon

take an infrared thermometer and check the risers to confirm if it's reading properly, sound like the stat is stuck open now if the sender is reading properly

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2001 328 Vista "Nauta Dream 2"
AB Inflatable 10AL "Little Dreamer"
2000 248 Vista
1997 225 Sundowner


Mike

My 2001 had 160 thermostats

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2001 Four Winns 298 Vista
Twin 5.7 Volvo Penta GSI DP

I put 2 new OEM ones in they are 160, and both motors run consistantly at 160 confirmed by my engine gateways hooked up to my Axiom. I watch them quite a bit. i don't trust the stock analog guages. BTW my 01 had a lot of rust flakes/rust in there and they were hard to remove, wondered if they were working at all.....IDK.

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2001 Four Winns 298 Vista
Twin 5.7 Volvo Penta GSI DP

If the engine is running way too cool I bet what you will find, is rust flakes from the intake manifold stuck in the thermostat so that it never closes all the way. This will for sure cause very slow warm up, sometimes they will dislodge when running on plane but sometimes they don't. I have started removing the stat at the beginning of each season and cleaning it, the housing and the intake out so that I'm at least starting with no rust flakes there to cause this issue. One of the many draw backs to raw water cooling. With closed cooling you would never have this issue...

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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

While the stat may be new, there will be rust flakes a plenty in the old cast iron intake manifold. That's why I have taken to cleaning it out in the beginning of the season and testing the thermostat in a pot of heated water. You have 18 years of raw water cooling in a cast iron engine, that's what happens. After I took my old engine apart last year to repair the blow head gaskets, I'd never have another raw water cooled engine in any inboard that I have here in salt water. Just installing a set of re-man heads, alone, dropped the running temp about 15*. That tells you how much rust and sediment was in the head water passages, impeding cooling. The block/crank/pistons/rods/cam/lifters etc are original and I'll run it as long as it lasts, then re-power with a new GM marine long block with closed cooling.

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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