How cold is to cold ?

[fishnfireman]

2013 300XS 1E051919 With SM lower unit and the forward facing water pickup
Water temps low 50's __ Air temps about the same.
What do you feel is safe operating temp (lower range) while cruising 4500 5500 RPM's

[rocketman6965]

On Monday in Florida, Air was 60 water was 65 degrees. Thermostats cycling perfectly at idle. Temps at cruising speed were 109-112.

[fishnfireman]

I saw from 104 to 108..
With the low water pickup the faster I ran the more water pressure I got and the lower the temp.
Made sure it came up to temp on every move. But with the cold water sometimes it took forever..

[rocketman6965]

I know Don explained it to me one time ram pressure has a lot to do with it and our setups run a lot faster at 4500 than a 23’ open fisherman let’s say so, it’s only natural we would run cooler.

[rocketman6965]

Double post. Sorry.

[06 SB]

It is my understanding that cruising temps really do not matter. Did your motor warm up to 120 at idle? I was out yesterday with water temp at 48 and outside was about 45. My temps just cruising around were 110-115. I have seen significantly less than that in really cold water/air temps. In all cases my idle coolant temp stabilized above 120.

[fishnfireman]

Yes Sir at idle it would stabilize 120-124.

[SilverFox579]

What does air temperature have to do with coolant temperature?

I was out 4 weeks ago in 44° surface temps and my coolant temps at cruise (4200rpm) were 80°. I'll be on the water tomorrow and already know surface temps are now around 42° and also know my cruise temps will be in high 70s.

[EuropeanAM]

It is my understanding that cruising temps really do not matter. Did your motor warm up to 120 at idle? I was out yesterday with water temp at 48 and outside was about 45. My temps just cruising around were 110-115. I have seen significantly less than that in really cold water/air temps. In all cases my idle coolant temp stabilized above 120.

+1

Cold water temps may be way lower when on plane... keep in mind this engine has to be able to run in sub-artic to tropical climates.

[SilverFox579]

Here's numbers from yesterday, water surface temp 39.7deg and coolant temp on plane at 4kprm 71deg. I take 2.5 - 3mi to reach cruise in those temps, and always after I first bring engine to thermostat temperature and at least one cycle before gradual acceleration.

[fishnfireman]

[SilverFox579]

Air temp was 39.4 but a comfy 58deg inside with the heat on.

[EuropeanAM]

2013 300XS 1E051919 With SM lower unit and the forward facing water pickup
Water temps low 50's __ Air temps about the same.
What do you feel is safe operating temp (lower range) while cruising 4500 5500 RPM's

As long as you let the engine reach operating temps AT IDLE, and made your acceleration gradually- the engine can run as low as 50-70 degrees F at higher RPM's, and be fine doing so.

See the FAQ section for more info on Cold Water Operation.