RPM Limiter / Overheat signal

94Sailfish

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On the water recently, my port engine's rpm limiter kicked in (in other words, it ran hot). However, the gauge did not signal an overheat nor did it give the beep warning. Where should I begin to track this down? Is there a way to manually send a signal to the gauge just to check the arrow and the beep?
 

94Sailfish

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No light or arrow on the gauge. So, working from the gauge backwards, I was hoping I could somehow manually cause the light/arrow to come on just to check its functionality.
 

CaptKennyW

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If you cant find the problem try the sensor itself I kept getting alarm/limiter and replaced a lot of stuff (it needed to get replaced anyway) and we finally figgured out that it was the sensor. If you are running and the alrm goes off slow down and quickly take the cover off feel the backs of the manifolds, they should be warm to the touch and you should be able to hold your hands on them for a few seconds. If they are hot something isnt right if not it may just be a little $20 sensor. Just my particular experience hope it helps.
 

BobP

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How do you know it was running hot, in reality?

Did you stop and pull the cowl and place you hand one ach of the heads by the plugs?

What hapened when you did this?
 

CaptKennyW

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BobP said:
How do you know it was running hot, in reality?

Did you stop and pull the cowl and place you hand one ach of the heads by the plugs?

What hapened when you did this?

yup i did so did my dad, we didnt get burned...
 

94Sailfish

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I knew it was hot when the rpm limiter kicked in. When this happens, the engine starts running REALLY rough if you're above 2K RPM (according to my mechanic). He also said when that happens, come back to idle for a minute or two to let the engine cool, then go again. So, the limiter did its job in keeping the engine from burning up and forcing me to reduce speed to cool the engine. However, I got no beep nor arrow indicator on the gauge when the limiter kicked in.
 

94Sailfish

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BobP........
After dwelling further on your question, I guess I cannot rule out a false alarm. It is my understanding that when an engine runs hot (on my boat anyway),
- the rpm limiter kicks in to keep from burning up the engine (this it noticeable as the engine begins to run rough if throttled above 2000 rpm...according to my mechanic), and
- the arrow on the gauge lights up as a visual cue, and
- the beep alarm sounds as an audible cue.
So, when the limiter kicked in, I assumed the engine was hot though there was no arrow nor beep. After coming to idle for a minute or so to cool the engine (port), I was able to resume cruising speed at about 4100 rpm.
Now, all that being said, I did not lift the cowling to feel for overheating. Again, I guess I cannot rule out a false alarm if that is what you were thinking.
 

94Sailfish

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just-in-time....I have a 94 sailfish sportbridge with twin 200 Yamahas. If you were referring to the type/model of gauge, my panel is a three gauge configuration. Left and right gauges are for the port and starboard engines respectively that indicate rpm, trim, oil, and temperature. The center gauge indicates speed, battery, time, and trip.
 

BobP

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Well it's up to you, it is posisble the limiter circuit is activating falsely and more importantly you do not want to over heat your powerhead so finding out if is really too hot is key.

If you are a DIYer and in safe waters when it happens, and want to know if the engine is really too hot, shut the engine off when you get the alarm, pull the cowl, and tilt up the engine a bit to feel the heads, each one, by the plugs. That's where the sensor is for the circuit and high temp alarm. If you can keep your hand on it at least for a while, it is not overheating. Besure to check both heads and the full height.

If it is too hot, you will know right away when you touch it.

The dealer will perform this sea trial service, probably has a contact temperature gauge he uses, at a fee - by the hour.

There is a procedure in the manual to test the components of the circuit incl the temp sensor, should it not be overheating.

Good luck.