Overheat alarm on Evinrude

[bradford]

Maybe one of you fellas can point me in the right direction before I spend any money or make something worse. I'm getting an overheat alarm immeadiately upon start up with a cold engine. The engine ran great last time a used her, about 1 1/2 months ago. Went to crank her up in the driveway and am getting the alarm. I'm getting plenty of psi on the gauge and a solid piss stream out the back. I'm thinking maybe a bad connection or ground maybe? The engine is a 1990 Evinrude 225 looper. Any advice is much appreciated.

[tsubaki]

There are two of these, on the rear right and left of the motor.
http://i175.photobucket.com/albums/w159/tsubaki3/Picture205.jpg
The picture is of one that has been spliced. The actual connection folds apart. Find each one of these, disconnect them and crank the motor. While running reconnect till the horn comes on, that will be the bad sensor.
http://www.wellcraftv20.com/community/showthread.php?t=7633&highlight=getting+to+repairs

If I'm not mistaken, it will start the horn without the engine on, just the key switch turned on.

[bradford]

I'll go try it now Thanks bro!

[bradford]

Well tsubaki I disconnected both of them and got the alarm still!

She sounded a little rough so I shut her off. I hope it's nothing serious.

[tsubaki]

Now, if you do happen to find it to be one of the sensors, be sure and determine if it is acting up when cold or if it is after the engine has ran a while.
If when cold, probably the sensor is bad.
If after running a while, could be a stuck thermostat or blockage somewhere.
If you have to change the sensor, do both of them and the thermostats also.

[THEFERMANATOR]

Is the oil injection gone completely? Try unhooking the fuel restriction sensor by the fuel pump, that can also trip the buzzer.

[tsubaki]

Do you still have the oil injection system connected?

[bradford]

Does it matter that my tach is presently disconnected?

[bradford]

Do you still have the oil injection system connected?
VRO disconnected, all premix

[tsubaki]

FERM's right. All the horn, oil and sensor stuff is connected together and tripped by the ground. Any of these can be the culprit.

[tsubaki]

The tach needs a pulse hot and a ground to operate. Depending how the boat was wired it could create a problem but I would expect it to be in reverse. Nothing working while disconnected

[tsubaki]

I have no idea where the book to my motor is. Was gonna trace the path and color of the horn wire to see what we might have overlooked.
Does the horn come on with the key switched on or only when the engine is running?

[THEFERMANATOR]

These pictures should be of the same set-up as yours as I have a 90 powerhead and early style harness. If you disconnect these 3 sensors and it still goes off you probably have a harness problem. There is also a chance that the self test portion of your hot horn has failed and stuck on. You can get a test light and connect the ground clamp to a 12V+ source and probe the brown hot horn wire and see if the light lights up. If it does then you probably have a harness problem. Also try unhooking the brown wire from your horn while leaving the key on and black ground connected. If the horn sounds it's defective, if not then your getting a ground in the harness. It doesn't take much to set the self test style horns off.

Here is the starboard overheat sensor.
http://i162.photobucket.com/albums/t271/THEFERMANATOR/WELLCRAFT/200E-1.jpg

Here is the port overheat, the one that hooks to the brown wire is the overheat and the white and black goes to the power pack.
http://i162.photobucket.com/albums/t271/THEFERMANATOR/WELLCRAFT/200E-2.jpg

And here is the fuel restriction sensor, you can also see the VRO amphenol in this one just to the right of the starter.
http://i162.photobucket.com/albums/t271/THEFERMANATOR/WELLCRAFT/200E-3.jpg

[bradford]

I have no idea where the book to my motor is. Was gonna trace the path and color of the horn wire to see what we might have overlooked.
Does the horn come on with the key switched on or only when the engine is running?

The first time the engine would run for maybe 5 seconds and then the alarm would come on. The second time it would come on after turning on the key.

[tsubaki]

Basically, the way the horn sitiation works is a constant hot thru the key switch, the ground will be derived thru the 2 temp sensors and any of the VRO system. If any of them trip it sends the ground path from the motor block to the horn.
You may disconnect the VRO and not interupt the water temp portion and visa versa.

[bradford]

Ferm, on the fuel restriction sensor, I should just disconnect the black wires?

[THEFERMANATOR]

Ferm, on the fuel restriction sensor, I should just disconnect the black wires?


One of them will hook to a ground wire, and the other should have a bullet connector on it. Unhooking either of them will take it out of the loop. Which style horn do you have now, 2 or 3 wire?

[bradford]

One of them will hook to a ground wire, and the other should have a bullet connector on it. Unhooking either of them will take it out of the loop. Which style horn do you have now, 2 or 3 wire?

Both the black wires are grounded to the fuel pump mount. I pumped my primer bulb and felt some resistance and then the resistance gave way. I fired her up and got no alarm at all. I reconnected the temp sensors and still no alarm. This doesn't make sense though if the fuel restriction sensor isn't connected to anything. Starting to think some crud in the fuel line to cause the rough idling, but dumbfounded on the alarm.

[bradford]

One of them will hook to a ground wire, and the other should have a bullet connector on it. Unhooking either of them will take it out of the loop. Which style horn do you have now, 2 or 3 wire?

I guess i need to pull the cover off the control box to find that out?

[tsubaki]

It sounds like the fuel sensor is connected and working and you did have a restriction and this would account for the rough running.

[THEFERMANATOR]

The restriction sensor only goes off if there is roughly 8-10"s of vacuum present in the fuel supply line. If you pump the primer bulb up to pressure then there will be no vacuum as you'll have pressure instead. The rough running could just be the gas in the carbs has mostly evaporated and left the oil behind. This is common if you let the engine sit for 2 or 3 weeks or longer with fuel left in the carbs. If both of the wires from the fuel sensor are grounded, then it is obviously not connected. Does your horn normally sound for a second when you turn the key on? If so then you have a 3 wire horn. They can malfunction and alarm even though there isn't a request for it to sound.

[bradford]

The restriction sensor only goes off if there is roughly 8-10"s of vacuum present in the fuel supply line. If you pump the primer bulb up to pressure then there will be no vacuum as you'll have pressure instead. The rough running could just be the gas in the carbs has mostly evaporated and left the oil behind. This is common if you let the engine sit for 2 or 3 weeks or longer with fuel left in the carbs. If both of the wires from the fuel sensor are grounded, then it is obviously not connected. Does your horn normally sound for a second when you turn the key on? If so then you have a 3 wire horn. They can malfunction and alarm even though there isn't a request for it to sound.

The alarm never sounds on start up so I guess I have a 2 wire? I'll start her up again and report back.

[bradford]

Started up again and let run for several minutes... No alarm, no idle problems, sounds strong as usual. Might be a case of needing to "Jiggle the Handle"

[THEFERMANATOR]

Or just run her some.

[bradford]

Or just run her some.

Roger that. I've only taken her out 4 times since February but I usually fire her up in the driveway once a week or so to keep fresh gas in the carbs. Maybe I got a little slack last month.

Tsubaki and Ferm I owe ya'll some beers. Thanks!

[tsubaki]

Hell, I had so much faith that you had it fixed that I went out to eat while you tried it!!!:sun:

[BigAl331]

And here is the fuel restriction sensor, you can also see the VRO amphenol in this one just to the right of the starter.
http://i162.photobucket.com/albums/t271/THEFERMANATOR/WELLCRAFT/200E-3.jpg

Sorry to bring up an old thread but I was hoping it would help me out. Instead it has raised another question that I hope you guys can help me with.

When at full throttle I get a buzzer that seems to be fuel related. If I slow down to about 1/2 throttle or less the buzzer will go away. The last time I took the boat out and the buzzer went off I immediatly went back and felt the collant discharge from the motor. It was the same temp as the surrounding water, so I'm assuming that it's not heat related.

Now to my question, is the fuel restriction sensor located somewhere other than the motor? I just looked all over the motor for a sensor that looks like the one above and couldn't find anything.

Fuel line comes in to the fuel pumps (straight to the upper pump). Then to the lower and on to the carbs. I don't see anything that looks like it would be picking up a vacuum from the fuel line. The is nothing in the incoming fuel system that has two wires coming out of them but the start/choke solenoid.

Any suggestions?

[THEFERMANATOR]

The restriction sensor is on the 86+ 200+ loopers and a few of the late model 150/175's. Older pre-VRO engines didn't have them.

[BigAl331]

Any reason why the buzzer keeps going off if it isn't overheating and there is no fuel restricted sensor?

[Skools Out]

well first off how is it going off? those buzzers have codes as to how they beep, is it solid or a long or short or both long short buzz?

[BigAl331]

It is constant. When it comes on I throttle back and I have felt the water coming out. It doesn't seem hot, same temp as surrounding water.

[THEFERMANATOR]

This is on the 82 150 you posted about in other posts? If so the only warning on it should be overheat.

[BigAl331]

This is. If it is an overheat then why is the water coming out of the discharge cool? The last time it went off I idled back and felt the water coming out and it was cool.

I'm confused on why it only happens at WOT.

[THEFERMANATOR]

The water coming out of the pee hole comes out from where the water first enters the powerhead if IIRC on the cross-flows. It would always be cool. I would check your bypasses for the T-stats if it was mine and make sure they are opening. Also how old is the water pump impeller? A weak impeller will give low water pressure at higher RPM's and cause the bypass not to open and cool the engine off under load. When the horn is going off next time put your hand on the block and heads and see if they are hot or cool to the touch. You could have a back feed in the harness setting the buzzer off.

[BigAl331]

Thanks. I am looking to replace the impellor, I don't know how old it is. I'll look at the t-stat to see how the look.

[BigAl331]

Looked at the T-stats today. I think I found my problem. Whoever changed the last used a sh1t load of RTV silicone and mostly blocked the passages.

The pressure release valve was slightly melted. Is this release valve used to prevent overheated condition?

The T-stats open at about 160 deg, both of them. So I put them back in. I'll try to take the boat out tomorrow and check them.

[THEFERMANATOR]

The bypass is meant to open when the engine reaches roughly 3000 RPM's so that the T-stats are bypassed when the engine is running under load. @ strokers tend to need alot of heat at low RPM's to burn the fuel mixture, but under load they want to be run around 100-130 degrees to prevent a piston from sticking. The water pressure that the water pump produces is what opens the bypass on your engine, so a weak impeller will not make enough water pressure to open the bypass. Also the T-stats don't flow enough water at speed to allow the engine to run cool, so the bypasses are a requirement to allow the cooling system to function at all RPM's.

[BigAl331]

I see but the water passages in the t-stat housing were partially blocked by the RTV. Even if the bypass did open I wasn't getting good water flow around the head, no matter the impeller condition.

I'm going out later to see if there is an improvement. The impeller is next on the list. I going to change it anyway.

[bradford]

It might scare ya to see what that impeller looks like. Could be "not too bad", or "HOLY $&%!".