Normal Engine Temp Raptor 400

[jcarter20]

Over the weekend I noticed something that I have never really paid attention to before. I have a 2018 Craz with the Raptor 400 in it. The normal operating temp when cruising around 25 mph, surfing, wakeboarding etc. Seems to be just above 160. However, we were on a larger lake and cruising around 35 mph (probably around 5000 rpm) for a few minutes. The temp got up to 179. As I backed down in speed, the temp would drop to mid 170's, but never back into the 160's until I got down to around 25 mph. Is that normal? I thought that seemed pretty hot. I replace the impeller every year, so it only has about 40 hrs on it. I am going to check anti-freeze to make sure it isn't low, but it was at the low line "cold" before we left for the trip. Just curious if everyone else sees that higher temp at higher speeds.

[Stazi]

When I surf it will get up close to 180. It then cools to 160-165 after I stop and idle a few seconds. Not an issue. If you start creeping north of 190 I’d worry.


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[larry_arizona]

Also depends on lake temp. But yeah 170 is still plenty cool.


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[jcarter20]

Cool. I wasn’t too worried when it came right back down, but I had never really seen it get that high before (or I hadn’t paid attention at least). All my other boats ran much cooler.

Lake temp was about 87.....it was nice! [emoji12]


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[larry_arizona]

Cool. I wasn’t too worried when it came right back down, but I had never really seen it get that high before (or I hadn’t paid attention at least). All my other boats ran much cooler.

Lake temp was about 87.....it was nice! [emoji12]


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Same engine in a truck application runs probably 210f.

Cooler isn’t always better to make HP.

GM LS engines prefer low 200’s for peak performance.




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[jason1973]

mine floats between normal 167 and have seen it up to 173.

[jcarter20]

Yeah must be normal. My antifreeze level is normal. I guess if you run it near wide open it will heat up pretty good.


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[spatty99]

Mine is usually around 165, hottest I've ever noticed was about 169 (used in central Florida, so water and air temps max out around 90 and 95 respectively).

[Swervy]

Hi, my 2018 Max had overheating issues a couple weeks ago. Brought it to the dealer, they went through it and flushed the coolant. I was told to keep an eye on the coolant reservoir. I’ve been out 4 times since getting it back and had to fill the reservoir each time before next use. Does this seem normal?

[larry_arizona]

Hi, my 2018 Max had overheating issues a couple weeks ago. Brought it to the dealer, they went through it and flushed the coolant. I was told to keep an eye on the coolant reservoir. I’ve been out 4 times since getting it back and had to fill the reservoir each time before next use. Does this seem normal?

Not normal, if you have a heater, check that the hose clamps are tight.


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[Swervy]

Not normal, if you have a heater, check that the hose clamps are tight.


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I do have the heater, I’ll check that out. I’m a complete newb with inboards as we just picked up the boat in June, where are the clamps located. It’s a raptor 400 if that matters

[larry_arizona]

I do have the heater, I’ll check that out. I’m a complete newb with inboards as we just picked up the boat in June, where are the clamps located. It’s a raptor 400 if that matters

My heater is located under a carpeted cover right at the engine cover opening. Two screws to remove cover and the heater pump is right there.

The heater hose then runs down the port side of the engine, SC uses crimp clamps, you need special pliers to tighten them or replace them with worm gear clamps.

Mine had a slow drip and I would need to refill maybe half a reservoir every 10 hours. Tightened clamps and never dropped coolant again.


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[MELVIN]

At what temp does the heater start blowing warmer air? New to inboards, too.

[Holdmybeer]

At what temp does the heater start blowing warmer air? New to inboards, too.

Your heater circuit is part of the closed loop anti-freeze with your engine. The heat exchanger will never go higher than engine temp. My boat at normal cruise is 167 so I wouldn't expect air to be much higher than 120 with thermal loss from the fan blowing.

[HFarr]

Yep to what HMB said. Just think of it like your car or truck. Air won't get warm until the engine temp or coolant gets up there. Unless you have a Tesla of course.

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