How does an Idle Stabilizer work?

[KCLOST]

My 1986 Merc. 175 Black Max has one and was wondering how it basically works.. <br />And, is there any way that you may know of that a faulty one can cause false/higher temps on an outboard.. (I've heard of that happening from other posts)...<br /><br />Is there a way to test it?

 

[Laddies]

Re: How does an Idle Stabilizer work?

It senses a low idle RPM and advances the timing to bring the RPM up

 

[Laddies]

Re: How does an Idle Stabilizer work?

Soory for the 2nd post for some reason my edit don't seem to work, to test the stablizer set the idle speed at 600 rpm and with a timing lite attached to the engine ck the timing then turn the idle speed screw out and the stabilizer should advance the timing as much as 9 deg.

 

[KCLOST]

Re: How does an Idle Stabilizer work?

Thanks Laddies,,,<br /><br />Can a faulty one possibly cause an overheat condition?

 

[andy6374]

Re: How does an Idle Stabilizer work?

KClOST-<br /><br />Physically, I can't think (unless my imagination is darn outlandish) of how the stabilzer could cause an overheat condition. It has nothing to do with the cooling system. The only thing I can think of is if it is advancing the timing at WOT, even though it is only supposed to operate at low idle, and the premature spark is burning you out. Do you have good compression? This might indicate if the spark is to advanced.<br /><br />What are your operating temps? My black max runs hot at WOT too, nature of the beast?.<br /><br />-andy

 

[KCLOST]

Re: How does an Idle Stabilizer work?

andy, I am just reachin out here...<br /><br />My engine runs at 180F after it runs at no wake speeds for awhile (1000-1100 rpms) and it will get up to 220F at WOT.... I have torn into everything as several other posters have also with no improvement... The stats, the poppet, water pump, water jackets, head gaskets, water jacket gaskets, and the compression on the cylinders is all around 120-125 psi.... So I've learned to live with it and know that it's not damaging the engine especially since we are talking about metal temperatures..<br /> <br />But I read a post on another forum that indicated that the idle stabilizer was the cause of an overheat condition and it's replacement reduced the temps 30 degrees...<br />So I had to ask..<br /><br />By the way, I did notice that the red lead from my stabilizer is in seriously bad shape, cracked, and corroded/green where the wire is exposed at those locations...

 

[andy6374]

Re: How does an Idle Stabilizer work?

As far as idle stabilizers are concerned, I think the general consensus is that they are crap. Mine was ripped off during a rebuild. The mech said they are just as unreliable as the oil injection system on our generation of Black Max's. Not that this guy is god by any means, but he has proven, to me at least, that his knowledge of the Black Max is superb. He stands by his work to the point where he has given me free parts, free advice, and has walked me through problems over the phone.<br /><br />Just a thought (getting rid of the stabilizer)....<br /><br />As far as the cooling system is concerned I have a question. My engine starts spitting water out the tell tale and it isn't 143 degrees. Do the thermostats open when the water reaches 143 or is it more a metal temp? It was more like 100 degrees out the tell tale with a digital thermometer.<br /><br />-Andy

 

[rodbolt]

Re: How does an Idle Stabilizer work?

the tell tale water at low speeds is a discharge from the t-ststs. it should be warm to almost hot. some of the stabilizers also haad an ign advance feature for operation above 5000RPM. to test attach a timing light to #1. grab the timer lever and manually retard timing by pulling the lever fwd. as rpm drops timing should advance electronically,even though you physically moved the timer base. if its working you will see the timing advance. its to assist in low speed operation and shifts of engine load at low speeds.

 

[KCLOST]

Re: How does an Idle Stabilizer work?

The stats open when the "water" reaches the 143F..<br />The spitting is a result of a bypass that allows some water to exit the telltale even before the stats are opened.<br /><br />When they are opened you will see a full stream of water...

 

[andy6374]

Re: How does an Idle Stabilizer work?

I don't like the whole "Black Box" module (includes stabilzers and ign advance) idea. All the mechanical linkages, if they are set correctly and the engine is properly timed, should do all the job of providing the advancing and retarding of the spark. Thus if all the adjustments are near perfect you never have to worry about a timing issue. <br /><br />On the other with the "Black Box" modules, you have no control...if the electrical sensors are screwed up you get messed up timing. <br /><br />I like the idea of how (in conjuction with flywheel and flywheel magnets) the stator, trigger, and switchboxes form complete and closed ignition system. And all its energy is ultimately dervied from mechanical energy not some sensors that say advance this retard that.<br /><br />Just my opinion.<br /><br />-andy

 

[KCLOST]

Re: How does an Idle Stabilizer work?

Good point Andy,<br /><br />And If the timing is messed up "advanced" could this result in an engine that runs hotter than normal???????<br /><br />Anyone...?

 

[clanton]

Re: How does an Idle Stabilizer work?

Have you checked the pressure relief valve?

 

[andy6374]

Re: How does an Idle Stabilizer work?

Well if your timing is too advanced you will surely burn out your engine. <br /><br />But if your engine is running too hot, then so is mine (I'm right in the 205-220 range at WOT). In the combustion chamber isn't there temps around 500-600 degrees. So I don't think its unreasonable to expect the low 200's for WOT.<br /><br />People who say their engine is runnin much cooler are either measuring the temp of the circulating water or they have a spiffy new optimax that might have an advanced way of cooling the system.<br /><br />-andy

 

[KCLOST]

Re: How does an Idle Stabilizer work?

clanton, many times!<br /><br />I agree andy! I still think I need to replace mine anyway... I'll let you know what happens...

 

[gss036]

Re: How does an Idle Stabilizer work?

Andy/KCLOST, on another post, there was a picture of the top of the block with a hose coming off of water tap in the block, I assume this goes to the poppet valve, but doesn't one also come off this connection for a water pressure gauge? Do either of you have a pressure gauge? I would think a gauge would give some indication of water flow. I have never looked at mine and often wonder if it is functioning, but then again I don't seem to have an overheat problem w/1989 200hp carbed engine. I can put my hand on my heads and they do not feel all that hot, especially since the thermostats open at 143 degrees. I've got a temp sending unit on back order right now in an attempt to get my temp gauge working properly, it seems to be reading on the low end, around 100 degrees. Just thinking out loud here, don't know if it would help either of you.

 

[Barnacle_Bill]

Re: How does an Idle Stabilizer work?

The poppet valve on my 83 150 bolts into the starboard side of the motor just below the switch boxes. I believe thats where yours should be but don't quote me on that.

 

[gss036]

Re: How does an Idle Stabilizer work?

IBNFSHN, you are correct. I was thinking of where the water flow comes from that goes to the poppit valve. Following a lot of the post seems to indicate that if the poppet is dumping too soon that the temperatures will rise for lack of circulation or circulation too fast. I have read both theories. I know years ago a lot of the boaters would take out the thermostats thinking that would help on cooling the engine.

 

[andy6374]

Re: How does an Idle Stabilizer work?

Lets talk about the cooling system, operating temp, and temp sensors/switches.(80' V6 Black Max)<br /><br />-The temperature we are talking about is very dependent on what the sensor is measuring, i.e. water temps or metal temps. The temperature sensor on mine (and I think most V6 Black Max's) is longer, touches no water, and measures metal temps. Essentially, it is situated just above the combustion chamber. Since combustion temps are 500+, a temp reading of 190-220 is nothing. Most overheat switches (switch not sensor) are set to go off at 265 or 285 degrees, then you will hear the alarm. Of course operating temps are lower at idle.<br /><br /><br />Here's my question. Do the stats open when metal temps are 143 or water temps. Because if it is water temps, then your engine is much warmer (more like 170) than 143 when the stats open.<br /><br />-andy

 

[gss036]

Re: How does an Idle Stabilizer work?

The last time I had my temp sensor out trying to get it working, it is set in a plastic insert that keeps it from actually touching the metal. It works on resistance as the temp rises, the resistence goes down, then the gauge reads higher. <br />This was posted by RODBOLT a while back when I was trying to get my unit working:hello<br />you seem to have a handle on it. the temp sensor is a thermistor device. as temp goes up resistance goes down. less resistance means more current through the meter which means more magnetism in the meter movement which means more needle deflection. if you have a bad or corroded connection between the sensor and the gauge that means a fixed resitance and low current. if the gauge is not reciving a good 12v power supply it means lower voltage and therefore less current in the meter movement. I made a tester with a potentiometer from the ol radio shack. use a felt tip and make marks using your DVM for the min and max resistance value you wish to check. remove the send wire from the gauge. hook up the pot between the s terminal and ground. move the pot between the min and max marks you made. if the gauge does not respond it most likly is bad. the pot also works for most trim gauges,oil pressure gauges and such what nots. its also handy to test the overheat and oil alarms on the four strokes. hello<br />follow the brown wire from the sensor to the terminal block or bullet connector. disconnect it there. with the key on momentarily ground the dash panel side of the brown wire. the needle should deflect to full scale. the test you did on the sender must be done on the Ohms function with the gauge disconnected. the resistance should vary inversly from cold,about 2.6Kohms ohms, to about 80 ohms when hot(approx 140*. my numbers may be off due to the age difference of my book and your engine but that is how they all work. <br />I got a call about an hour ago telling me my new sensor is in, so will pick it up 1st part of next week. <br />I have also looked at the overheat sender, it is just a spring loaded pop type sender that opens when overheated, then resets itself as it cools down. It is really nothing more than a switch.

 

[andy6374]

Re: How does an Idle Stabilizer work?

My sensor has that plastic insert as well, but I thing that is just so it doesn't melt the tan wire coming out of the head. I think the actual sensor is goes further into the head and measures metal temps. <br /><br />I could be wrong. This has been a topic of hot discussion. Because mine engine runs great, the overheat switch (or alarm) never goes off, but I run 220 at WOT.<br /><br />Opinions?