How to detect overheat potential before it happens??

[Beachbummer]

230F and Thermoswitch shows "Off" ...I did not expect it to run that hot! I expected lower than water boiling point. Thanks for the data!!!! My plan is to measure water flow and temperatures at a few different places and see where that takes me.

 

[Scottie]

I added temp gauges with sensors in the cooling output lines. It actually works quite well. Obviously it will read an increase in cooling water temp, but apparently there's also an increase in air temp when cooling water isn't present. I've tested this and watched the temp rise. On my 2013 212x, normal temps are around 100 degrees, climbing as high as 125-130 when dropping immediately to idle from an extended high rpm run.

 

[Scottie]

it's a "indicator flow line"

@buckbuck am I making this up or did you determine the engine actually cools better at higher rpm with more water flowing ?

This is accurate. My engines run cooler at 7500 rpm then they do at 2000. Tested and verified.

 

[buckbuck]

@Scottie I can't remember when Yamaha changed the engines on the 212X. Do you have the 1.8's or MR-1's?

 

[Scottie]

I have the 1.8l HO's

 

[buckbuck]

So 7500 is close to WOT for you. Where as that is my cruising rpm. It is interesting that Yamaha has got the cooling dialed in pretty well for your engines.

 

[Beachbummer]

Where did you add the sensors? On the pisser line? or on the outflow going to the transom? Those look NICE

 

[Scottie]

I added the temp senders in the output lines, the "pissers" . I originally had mechanical needle gauges, but they wouldn't read low enough. It just looked like the gauges were always broken. I went way overkill with the installation, with brass fittings in the lines for the senders. Could definitely do it cheaper/easier, but I had most of the parts on hand, believe it or not. The first set of senders I used expected a grounded mounting location, so what I had was perfect. The ones I have installed now have a pigtail for ground and signal, so plastic could easily be used.

 

[Ratket]

I added temp gauges with sensors in the cooling output lines. It actually works quite well. Obviously it will read an increase in cooling water temp, but apparently there's also an increase in air temp when cooling water isn't present. I've tested this and watched the temp rise. On my 2013 212x, normal temps are around 100 degrees, climbing as high as 125-130 when dropping immediately to idle from an extended high rpm run.
View attachment 101985

@Scottie

You would happen to be able to toss together a write up and a parts list would you?

 

[Scottie]

@Scottie

You would happen to be able to toss together a write up and a parts list would you?

I'd be happy to, and was planning on it, which is why I had the pics. I have a couple of write-ups I was planning that got delayed when a bearing or two exploded. ?

 

[Beachbummer]

Nice!! Did you get this on the ones closest to the back? or the ones that are closest to the bow?

 

[Scottie]

Nice!! Did you get this on the ones closest to the back? or the ones that are closest to the bow?

I cut the hoses between the engine output and the "pisser" fittings. My hoses were easily accessible just under the forward lip of the engine hatch, before the hoses pass into the starboard side storage compartment, just above the air filter box

 

[Scottie]

@Scottie

You would happen to be able to toss together a write up and a parts list would you?

Write up posted. https://jetboaters.net/threads/how-to-install-temperature-gauges-and-senders-for-engine-temps.23774/

 

[swatski]

Write up posted. https://jetboaters.net/threads/how-to-install-temperature-gauges-and-senders-for-engine-temps.23774/

Awesome writeup!

Totally makes sense, your measurements/gauge readouts. You can feel those temp difference exactly with that pattern using your hand at a pisser at those engine speeds/RPM.

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[the MfM]

Do a search on eBay for “12v temperature meter”

You can get all kinds of digital meters (round, dual output or with an alarm) with a thermistor type sensor that are surprisingly accurate and long lasting. I’ve been using them on my boiler to measure supply and return temps at various points. I’ve just got the sensors wire tied in place. 8+ years without a failure. Around $5 a piece shipped.

 

[Cambo]

Maybe after 20 years I can hear and feel cavitation and know that the flow is not correct. Luckily I have never gone into limp mode but did have an engine light come on checked the pissers they were flowing fine when the boat was pulled a branch was wedged behind the impeller. The cavitation could be felt I checked the clean outs for sea grass but it was clean the sound and vibration are different with cavitation it was very slight just pay attention. The thermostats look like a great safety feature that will be my next modification

 

[2kwik4u]

SO, they make these things for cars, wonder if it's available (or there is a market for) for boats.

ScanGauge II

I mean this is what we're really after right? A way to add 4-5 sensors, and have access to the sensors already on the engine. Some sort of small display, and a means of toggling through the various inputs/outputs on the display.

Do they make such a thing for the NMEA standard? Does Yamaha allow that data to be read outside of the proprietary software? This doesn't feel like a terribly difficult project for an enterprising electronics guy with some spare time

 

[Scottie]

SO, they make these things for cars, wonder if it's available (or there is a market for) for boats.

ScanGauge II

I mean this is what we're really after right? A way to add 4-5 sensors, and have access to the sensors already on the engine. Some sort of small display, and a means of toggling through the various inputs/outputs on the display.

Do they make such a thing for the NMEA standard? Does Yamaha allow that data to be read outside of the proprietary software? This doesn't feel like a terribly difficult project for an enterprising electronics guy with some spare time

The same roadblock as always, unfortunately. If you have a Yamaha outboard, then a simple connection to any nmea2k compatible display would get you the info you've mentioned. (Simrad Go series for example). BUT, for Yamaha JET BOAT engines (skis too), the data does not fully conform to nmea2k standards. Some of it does, (speed and water temp data is available) but most other data (rpms are usually what people are after) is a combination of proprietary pgns and nmea0183, which no display can read without assistance from mother Yamaha. So short answer is yes, they do make such a thing for nmea, but that is not relevant for us, unfortunately.

 

[biffdotorg]

So for those that have been monitoring temps, there may be some best practices to follow?

I'm guessing, that pulling hard when towing should probably be followed by some nice high-idle time to keep water flowing. Rather than run them hot till a kid falls of and then immediately kill the engines. They may need that 30-60 seconds of water flow just to cool down a bit before killing them.

That may have been why my overheat came up when I tried to restart. These gauges would tell that story. But once figured out, a good habit could be formed to avoid it.

 

[Scottie]

So for those that have been monitoring temps, there may be some best practices to follow?

I'm guessing, that pulling hard when towing should probably be followed by some nice idle time to keep water flowing. Rather than run them hot till a kid falls of and then immediately kill the engines. They may need that 30-60 seconds of water flow just to cool down a bit before killing them.

That may have been why my overheat came up when I tried to restart. These gauges would tell that story. But once figured out, a good habit could be formed to avoid it.

Exactly. The more rpms the better, for cooling purposes. While I don't think you can really do any damage assuming all other functions are normal, shutting the engines down immediately from a high rpm run definitely spikes the temps. Idle will help, high idle will help more, and a nice easy cruise (5k rpm or so) is probably best, when possible.