Engine Temp Reading While Underway.

[magicalbill]

My 232 has twin 2006 Yamaha F200's with 754 hrs. on each.

I normally run with the display of engine temp, battery and oil on my gauges. You all know, the 3 flat lines with the little arrow above each line that moves right or left, depending on the reading it is indicating.

My engine temp, (the top line) runs right in the middle, which I was told is normal. However, when I run over 4100-4200 RPM for a sustained period, 5-6 minutes or more, the arrow moves to the right one notch, indicating a slight overheating, I would guess. This happens on both engines, although the stbd one moves over quicker than the port one. As soon as I drop off plane, or slow down to 3600-3700 it returns to the middle position, to stay there until the next period of 4100-plus.

My tech says this is not cause for concern. He said alarms will start blaring if real overheating is imminent. He also stated that we can put a computer on it, run it and look for the sensor that is causing it, but suggested that I go on and not worry.

Most of you guys run Yams; has anyone experienced this? Would any of you worry about it? Has anyone positively identified the problem if there is one?

Thanks All..Always appreciate the feedback here.

 

[wspitler]

Happens to my F250s on every long run. I bought the YDIS software and cable and hooked it up (not expensive on Ebay). Don't remember exactly, but the middle is 175F or so and each notch is 5 or 10 more. A good Yamaha tech should be able to tell you what the numbers are for your set up. Overheat is higher and you would likely see it pegged to the right before the buzzer went off. As I remember it the buzzer and temp indicator are separate sensors. Overtemp alarms are usually just switches and gauges are often driven by a thermistor. When I first noticed it on my engines 4 years and 300 hours ago, it concerned me a bit. New water pumps didn't change it. I haven't changed thermostats, but my guess is that the thermostats don't fully open until one notch to the right if center. I can run all day at one notch right.

 

[suzukidave]

it is likely normal temperature increase as you ramp up the load to the engine. your engines are not overheating just because the temperature increases. a 4 stroke has a normal optimum operating range of at least 170 to 200 degrees depending on engine load and rpm. most car temperature gauges since the 1990s are "dumbed down" so they do not even move over that range to avoid dealers getting calls from anxious customers.

if the temperature steadily climbs as you increase rpm all the way to maximum rpm it could be because you are overpropped, which is the equivalent of trying to drive a car in too high a gear.

 

[magicalbill]

Thanks! The replies are appreciated.

Between my tech and your answers, it doesn't seem like something to worry about. As long as I'm not causing any engine damage from overheating, I'll carry on.