www.iFourWinns.com

Hello,
I've a problem with the cooling of the OMC 4.3GL in my 1995 Horizon 192.
After planing the temp gauge falls down from 160 degrees to something between 100 and 120 and never comes up on the trip.

Last year there was some "mud" in the bypass of the thermostate housing and the machine couldn't heat up.
This year the bypass is clean, but it comes to such problems.

Next weekend I'll check the impeller. Moreover it could happen a problem with the ground line of the engine. The line of gauge I checked already, they are okay.

Furthermore I recognized, that the left exhaust pipe is more warm, than the right one.
It is not really hot, but warmer. I can't meassure it, but I can leave my hand on it, so it is not more than 170 degrees.

I know, it can depend on the mounting position of the cylinder of the V-engine.
Did Somebody noticed the same?

Make sure your thermostat is not sticking. I sucked some sand up a couple weeks ago and it caused my thermostat to get stuck open. It was acting erratic for half of the day until it fot sutck open and ran below a 120 degrees at all times.

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2014 Four Winns H180 RS
14' 70's Lund

Next weekend I'll open the thermostate housing to have a look at the thermostate.
I have already ordered a new thermostat precautionarily.
Additionaly I'll check the impeller.

I second the sticky thermostat issue. It is more or less a chronic issue with raw water (sea water) cooled engines especially in salt water. Usually it is a grain of sand or a rust flake that stops the 'stat from closing. I have been able to fix this with the boat on the water by running it on plane to get the stat all the way open, then slowing down to idle and tapping the 'stat housing with a small hammer to dislodge the particle (don't laugh it works).
If you can keep your hands on the manifilds they are probably under 140 degrees because that's whst I've found when checking mine with an IR temp gun.
Mine are usually close to the same temp on each side. Idle temp = 100 or so, after running on plane = 125-130 or so.

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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