1990 Mercury 60hp constant beep/alarm..?

[Stephenmoore009]

1990 Mercury 60hp ELPTO: SN - 0C233349

Recently purchased, rebuilt carbs, installed new impeller, installed new rectifier.

Took boat out to test, started it up and pee stream was real good. Let idle/warm up for 2-3 minutes.. Putted out of marina and as soon as I pushed throttle forward and it got up on plain there was an alarm/buzzer, sounded more like a constant beeeep..! When I throttled back down to almost neutral it stopped. Took off again and same thing. Full throttle- alarm. Almost neutral- no alarm.

Oil injection has been removed, from what I've read in Clymer manual it supposedly had a remote oil tank near gas tank. I can't find any evidence of this, nor is there any extra or plugged off hoses anywhere.

Like I said I replaced impeller and it pee's a good stream, however I did not notice any grooves cut into any of the parts that may cause pressure loss. I don't think it was over heating because it only ran for 5 minutes max before alarm sounded.

And while I'm here, tachometer was reading 5000 or just over at full throttle, it by no means sounded like it was turning that many rpm's. It is a real quiet motor and sounds really good. But it took longer than I would have thought to get boat up on plain. It's a 1989 Astroglass 152 15 foot bass boat.

I tried to search through the forums and didn't have any luck finding similar problems I'm having.

Thanks in advance for any input..!!!

 

[Texasmark]

If oil injection is removed, I assume you are adding 1 pt of TC-W3 marine oil to 6 gallons of non-leaded gas in your tank.

I assume you got your water tube from the output of the water pump up to the bottom of the block secured properly with the necessary parts...seals if it uses them. With that in order the next order of business would be to check your thermostat. The stat on the 90 hp engine is set to open at 143F which is stamped on the pellet of the device. It's located under a small cover on the rear of the engine block water jacket (where the spark plugs are located). Some engines use a cooler stat so you need to check the stamp on the pellet for opening temp. A pan of water on the stove and a candy thermometer will tell you if it's working. If it's the original you ought to change it anyway. The OT warning is set to around 195F. If in fact you are setting off the OT alarm, the engine block would be very hot to the touch...like 2 seconds max and the exhaust may be steaming.

The larger engine and probably that one too has the pee plumbed off the exhaust manifold water jacket (follow the tube to find it) and is not part of the temp controlled cooling loop. So you could have good pee and a stuck shut stat.

 

[CharlieB]

Have you verified WOT ignition timing. If not, remove all spark plugs and ground all the plug wires. Attach a timing light to #1 plug wire. Either be very aware of the spinning prop, or go ahead and remove the prop. Shift into Forward gear and open the throttle all the way. This moves the timing linkage to max timing. Using a remote starter button or a helper to turn t he key. Look at the timing marks on the flywheel.

Incorrect ignition timing will increase motor temps at larger throttle, more load, and cool again at lower throttle settings.

 

[Stephenmoore009]

If oil injection is removed, I assume you are adding 1 pt of TC-W3 marine oil to 6 gallons of non-leaded gas in your tank.

I assume you got your water tube from the output of the water pump up to the bottom of the block secured properly with the necessary parts...seals if it uses them. With that in order the next order of business would be to check your thermostat. The stat on the 90 hp engine is set to open at 143F which is stamped on the pellet of the device. It's located under a small cover on the rear of the engine block water jacket (where the spark plugs are located). Some engines use a cooler stat so you need to check the stamp on the pellet for opening temp. A pan of water on the stove and a candy thermometer will tell you if it's working. If it's the original you ought to change it anyway. The OT warning is set to around 195F. If in fact you are setting off the OT alarm, the engine block would be very hot to the touch...like 2 seconds max and the exhaust may be steaming.

The larger engine and probably that one too has the pee plumbed off the exhaust manifold water jacket (follow the tube to find it) and is not part of the temp controlled cooling loop. So you could have good pee and a stuck shut stat.

Yes I bought an oil measuring bottle from BassPro. Mixing 50-1 ratio. That's what I was told to mix on another forum but it took a week or two before anyone replied so I came to this forum for maybe quicker help.
And it's a 60 horse not a 90, would the temp numbers still be the same..?
Also the pee hose when I follow it up from the (hole) goes into what I believe is the power head just above and to the right of the top spark plug.
If I can figure out how to post pictures from my phone I'll post some of the motor with the cover off to show you what I'm talking about.
Thanks for the help, I'll be posting an update soon.

 

[Stephenmoore009]

Have you verified WOT ignition timing. If not, remove all spark plugs and ground all the plug wires. Attach a timing light to #1 plug wire. Either be very aware of the spinning prop, or go ahead and remove the prop. Shift into Forward gear and open the throttle all the way. This moves the timing linkage to max timing. Using a remote starter button or a helper to turn t he key. Look at the timing marks on the flywheel.

Incorrect ignition timing will increase motor temps at larger throttle, more load, and cool again at lower throttle settings.

I'll check that out, so boat motors don't have to be running like a car motor to check timing..? I have a set of retractable wires with alligator clips, will that work to ground the wires..? Can I ground them from a spot on the motor or just run the wires to the negative battery terminal.
Also thanks for your help too..! I appreciate all the tips I can get..!

 

[Stephenmoore009]

I can't get the stupid photos to upload, the only thing I see is a tiny sensor on the right side of the top spark plug.
I've read my Clymer manual and it's no help really, all it says is that if the buzzer does not beep when the key is first turned on to replace the buzzer itself.
Mine does not beep when I turn the key on, is there a test I can do to see if the sensor is bad, or if it's a short in the wiring somewhere..? Also the wire looks to be made onto the sensor. I can't see a way to get it out and I've looked online and can't even find one that looks like mine..!!!
What do I do..???

 

[Texasmark]

You apparently have an OT modulation module which modulates the low oil warning to 010101010 whereas OT is just 11111111111111. If you don't have a module, I don't know where the horn would get the signal to honk.

The warning horn is in the wiring harness near the control or inside the remote control box (Merc/Quicksilver Commander 2000 and 3000). One side is 12v fed from a purple or red with purple stripe which is 12v switched on when the ignition switch is in any position other than OFF. The low side of the horn is floating. If you have an oil or OT fail it will ground the low side of the sensor. Without the module, either will just short to ground when in the fail mode and make the horn blow. With the module the signals from the sensors will go to the module and it will decide what type of grounding pattern is required for the horn.

The oil sensor wiring uses blue/white stripe (as I recall) and consists of 2 wires. The switch is in the oil tank and it connects ground from one of the wires to the other which goes to the module or low side of the horn. The OT sensor is buried in the rear water jacket (in the vicinity of the spark plugs and has a tan or tan/light blue striped wire coming out of it.

All to the best of my recollection!

 

[Stephenmoore009]

You apparently have an OT modulation module which modulates the low oil warning to 010101010 whereas OT is just 11111111111111. If you don't have a module, I don't know where the horn would get the signal to honk.

The warning horn is in the wiring harness near the control or inside the remote control box (Merc/Quicksilver Commander 2000 and 3000). One side is 12v fed from a purple or red with purple stripe which is 12v switched on when the ignition switch is in any position other than OFF. The low side of the horn is floating. If you have an oil or OT fail it will ground the low side of the sensor. Without the module, either will just short to ground when in the fail mode and make the horn blow. With the module the signals from the sensors will go to the module and it will decide what type of grounding pattern is required for the horn.

The oil sensor wiring uses blue/white stripe (as I recall) and consists of 2 wires. The switch is in the oil tank and it connects ground from one of the wires to the other which goes to the module or low side of the horn. The OT sensor is buried in the rear water jacket (in the vicinity of the spark plugs and has a tan or tan/light blue striped wire coming out of it.

All to the best of my recollection!

Ok thanks, my oil injection has been removed. I mix gas 50:1 with Mercury oil.
From what my Clymer manual says mine had the remote oil tank next to the main fuel tank and the horn for it was actually on the tank. Therefore I don't think it's an oil alarm I'm hearing.
I do however have a very tiny sensor right next to the top spark plug. Looks to me that it's right in the combustion chamber..? Maybe there is a water jacket that close I don't know. I really wish I could get my pictures to upload but I can't.
I sent a message to iboats about the sensor and the one they show for my motor looks to be bigger and made different than what's in mine.
I just want to be sure before I order it, it's almost 20 bucks and I don't really want to have to go through the hassle of sending it back if it's wrong. I will if I have to though.!
I do have a port to the left and just below the top spark plug as well with a brass plug in it, could the sensor they show be a replacement that fits in that spot..? I would need to make a new wire that would reach it but that would be no problem at all if it will work.
Again thanks for all the help.

 

[Stephenmoore009]

No Title

 

[Texasmark]

That's a ⅛" pipe thread where some people use a hose barb to attach a tube to a water pressure gauge on the dash. It is screwed into the water jacket cover that is over the combustion chamber...... there is crankcase water behind that flange. On that same flange, to the left of the #2 spark plug is where my OT sensor was located on a 90 hp triple. Has one screw on a little bracket with the tan or tan/light blue stripe coming out.

Go to the wiring harness plugs where the remote control electrical plug attaches to the engine's electrical connector. Look for the wire color mentioned. Follow it to the sensor.

On some engines/control harnesses, that color wire is not in the multi pin connector but zip tied to the harness with a single bayonet connector right there at the multi pin connector.

 

[Stephenmoore009]

That's a ⅛" pipe thread where some people use a hose barb to attach a tube to a water pressure gauge on the dash. It is screwed into the water jacket cover that is over the combustion chamber...... there is crankcase water behind that flange. On that same flange, to the left of the #2 spark plug is where my OT sensor was located on a 90 hp triple. Has one screw on a little bracket with the tan or tan/light blue stripe coming out.

Go to the wiring harness plugs where the remote control electrical plug attaches to the engine's electrical connector. Look for the wire color mentioned. Follow it to the sensor.

On some engines/control harnesses, that color wire is not in the multi pin connector but zip tied to the harness with a single bayonet connector right there at the multi pin connector.

Ok so the sensor is what is right next to the spark plug right.?
Since the wire is made onto it how does it come out.?
I just don't want to break it if it is still good.

 

[Texasmark]

Mine appeared to be a flat plate (from outside) held in place with a single screw and was teardrop in shape with the wire coming out the center. The sensor should be protruding out the rear, in the water for good contact. I never had to take it out so I don't know what they look like, but they are just a snap action single pole single throw switch that snaps when it gets too hot which opens the contact.....if you ever clicked a frog clicker toy and watched the center circle pop back and forth as you clicked it, you know what kind of device it is/probably is.

 

[Stephenmoore009]

Yeah I've seen the ones you are talking about but mine doesn't have a plate holding it in.
It looks like plastic or rubber with a 8 or 10 millimeter VERY flat looking nut in the middle and the wire is in the center of that.
It's so thin even if the wire wasn't there I don't think I could even get a socket on it.
I'm wondering if it's just pressed in with an o-ring holding it in place..?

 

[Stephenmoore009]

No Title

You can see here how thin it is. There is no plate holding it in. The wire is made onto it so I can't put a socket on it, and it's in a recessed hole so I don't think I can get a wrench on it either. I'm stumped..!!!

 

[Texasmark]

That's it. Before you tear into it, ohm it out. It should be open circuited between the wire you see and the engine block until it's sensor temp reaches about 195F at which time it shorts out grounding the low side of your horn and causing it to blow. Follow the wire back to the first bayonet connector and open it thus accessing the conductor there. If you don't know what I just said, I'll figure out an alternative.....light bulb and small battery.

I'll do it now: Get a 12v bulb, auto tail light (1157) is a good one for a number and touch the case of it, or a terminal if not round bayonet base to the red wire coming from the battery at your starter solenoid solenoid (for a spot to get 12v). Take the conductor of the end of the wire you pulled out of the wiring harness and touch the other bulb terminal.

If the engine is cool and the bulb lights, you have a shorted sensor, even if dimly lit. If not lit and you got good connections in your testing, and the bulb is good, then there is nothing wrong (essentially) with your sensor and you must have a short somewhere in your wiring harness.

 

[Stephenmoore009]

Awesome thanks, I'm pretty good with an ohmmeter. Lol
I'll check it out tomorrow afternoon and let you know what I figure out.
Thanks a bunch for all your input, it is greatly appreciated..!

 

[Stephenmoore009]

No Title

Finally got that bastard out, had to break the wire and use a deep well socket.
With the key on I used a test light on a ground wire and when I touched the end of the wire, the alarm went off.
That's the only time it would make it go off, (beep)...
Does that mean the sensor is good or bad..?
Also that thing is freaking tiny..!!! It has a 9/32 head on it..!!!

 

[Stephenmoore009]

No Title

This is it on the butt of a cigarette, that's how small it is. And I can't find it anywhere..!!!

 

[Texasmark]

Don't understand your test setup. A simple check would be to touch the wiring harness end of the wire you separated from the part going to the sensor, to the engine block...no paint, raw metal and with the key ON the alarm should sound. Reconnect the wires so that you have continuity from the wiring harness down to the sensor like it was originally. Turn the key on again. If you get a beep, it's shorted. If not it's ok.

On finding one, you can www for temperature sensors and find some suitable subs (I have done that in the past) for around $15 that can be used to sense temp. Anything rated for 1 amp is plenty......current is probably in the 100's of milliamps. Since you'd be glueing it to the outside of the water jacket, in the general vicinity of where the OEM is located, rather than in the water, I'd get one that with 2 wires or a wire and a metallic shell that CLOSES ON RISING TEMP, temp rating around 180 not 195.....that ought to work. I'd prefer one with 2 leads to ensure a better ground since you can put a terminal lug on the ground end and attach it to (under) a screw , like maybe a screw that is used to ground something else in the engine.

On the sensor, just glue it to the water jacket cover that the other is mounted in. I'd blob the glue on to make a cocoon sort of thing to assist in ensuring that the sensor gets a realistic reading of the plate temp, not the temp of the engine ambient air.

 

[Stephenmoore009]

ill do some searching online and see what I can come up with. I can always solder the wire back on and hook it back up.
ill also do a more detailed test and tell you what I find. there was one point I was touching the test light to the sender and just getting static through the alarm, but I don't remember if I was on power wire with key on or off. (ill write each test down as I do it tomorrow)
I know with the key on and test light hooked to ground, when I touched the sender (grounding it out) the alarm would sound constantly.
ill report back tomorrow with a more detailed report.
I may just order the one that goes in the 1/8 npt hole and see how that does, it goes straight into a water jacket. the tiny one I took out just threaded into a recessed hole in the cover beside the spark plug.