what to look for on gauges?

[boatman37]

newbie here. i am very familiar with engines (i used to race cars and built my own) but these I/Os are a little different. i'm used to seeing about 200-210* on the temp. from reading here that isn't typical on a boat? so what range should i be looking for and what is the danger zone? RPM about 4500 RPM max? 3200 or so cruising? anything else? boat is a 1986 Sea Ray Sundancer 250 with a 5.7 merc 260 carbed. anything else i should know or be aware of? thanks!

 

[Bondo]

Ayuh,..... Welcome Aboard,..... With a 160? t-stat, 170? to 180? might be seen,....

SBCs like a 4800 rpms at Wot,.... cruise at 'bout 75% throttles,....

 

[tpenfield]

Temp on the 5.7's should be in the 160-170 range . . . . 180 is starting to get hot. Oil pressure should be 30-60 psi.

 

[gm280]

With an I/O you have fresh water flowing through the engine and not a sealed radiator system. So the thermostat is going to control the temp. So observe the previous comments and make sure the cooling system is free of any obstructions. Fresh water can pick up some crappy junk out of some bodies of water...

 

[thumpar]

Mine usually sits a tick below 175 unless I am out on a really hot day it will sit at 175 on a long run.

 

[boatman37]

thanks all. i just got it back from a reputable shop (merc dealer) where they replaced the bellows, gimbal, water intake hose, impeller, and fluids. the bellows weren't that bad and the impeller was replaced about a year ago but i had them do it while it was apart. the main reason i took it in is that the intake hose was hard and cracked. i could see the cords through it. they said the water flow was good so hopefully there will be no issues. but every day i think of more questions, many dumb ones too...lol

 

[achris]

.... but every day i think of more questions, many dumb ones too...lol

As I tell my trainees, the only dumb question is the one not asked.