1982 Johnson 50 Sea Horse - Constant Beep While Accelerating

[Crosbyman]

you can probably test the sensing device by measuring it's conductivity (ON or OFF ........ 0 ohms or infinity) for a "switch" version

or... measure the gradual change in resistance value while you warm (heat) it up. for a resistance version .

if ok then I would suspect the buzzer... alarm cct.

report back on IR scan readings

 

[Grub54891]

The one I worked on, the beeper was under the dash.

 

[Mc Tool]

Tinnitus ?
Have we all seen the prank where someone attaches a harmonica to the underside of a car so it makes noise while car is mobile ?

 

[Elessar_94]

Tinnitus ?
Have we all seen the prank where someone attaches a harmonica to the underside of a car so it makes noise while car is mobile ?

It genuinely sounds like Tinnitus lol that ear-piercing ultrasonic high pitch noise. Maybe it’s not even the overheat alarm I’m buying a temperature gun tonight for this weekend’s lake test. Will update you all with some numbers soon.

 

[tphoyt]

Haven’t seen that yet but sounds fun. No Pun intended.
Someone put big wedges of blue cheese on my buddy’s exhaust manifolds while he was getting married. He said it smelled absolutely awful a mile down the road. No one has confused to this day. That was 40+ years ago but there is still time for a death bed confession.

 

[Mc Tool]

It genuinely sounds like Tinnitus lol that ear-piercing ultrasonic high pitch noise. Maybe it’s not even the overheat alarm I’m buying a temperature gun tonight for this weekend’s lake test. Will update you all with some numbers soon.

Ha ha ha, well thats all I could hear while listening to your vid .....could still hear it after vid ended .
Does it still do it with the engine cover off ?

 

[Elessar_94]

Ha ha ha, well thats all I could hear while listening to your vid .....could still hear it after vid ended .
Does it still do it with the engine cover off ?

Good question, I will test it with the cover off. I’m glad someone else hears it!

 

[Crosbyman]

Tinnitus ?
Have we all seen the prank where someone attaches a harmonica to the underside of a car so it makes noise while car is mobile ?

reminds me of my dodge dart from the 70s... one windshield rim caused a loud shreeeek at 50mph+ Dealer never fixed it ......I had to tape all the front trim on the car and peel off sections of the tape every mile on a highway run till I found the top windshield trim was the cause for the spaceship sound following me on the highway !!

 

[Mc Tool]

reminds me of my dodge dart from the 70s... one windshield rim caused a loud shreeeek at 50mph+ Dealer never fixed it ......I had to tape all the front trim on the car and peel off sections of the tape every mile on a highway run till I found the top windshield trim was the cause for the spaceship sound following me on the highway !!

My car starts making loud shreeeks at about 70mph, but they are mostly coming from the passenger seat

Ooooooh , I wouldnt mind having that car now .

 

[Grub54891]

My car starts making loud shreeeks at about 70mph, but they are mostly coming from the passenger seat

Ooooooh , I wouldnt mind having that car now .

Tyler and Marissa on Instagram: "Does anybody have this constant noise? #funny #gf #bf #couple #cars"

16 likes, 0 comments - outoffuel.oof on January 26, 2025: "Does anybody have this constant noise? #funny #gf #bf #couple #cars".

www.instagram.com

 

[Elessar_94]

UPDATE:

I tested the motor temperature extensively today. The highest number was 213 after a run, then averaged around 185 after that. All temperatures are in Fahrenheit.

Initial test w/ emmissiveness set to 70 (aluminum):
183
200
200
213
200
Changed emmissiveness to 90 (default):
180
175
173
174
Seems to be hottest on left side when facing motor from inside the boat

Second test (emmissiveness 80):
168
174
162
173

Third test from across the lake (emmissiveness 70):
180
189
187
165 on other side (right)
173 on other side (right)
180 on top
184
190 on left side
192
178 on right side
184 on top
185

Definitely overheating. All I can think of now is removing the cylinder head, replacing the head gasket and cleaning out the cooling channels. Thoughts?

 

[Crosbyman]

gaskets are cheap so may as well if nothing else works

 

[saltchuckmatt]

Now you need to know why your alarm isn't going off. That sequel you hear that I can't could be a failing horn.

Ground the tan wire with the key switch on....no sound, open up control box and hot wire horn and see if it's dead.

When I test for overheat at the first sign of going over 150...160 I shut her down.

Not sure if recommend doing what you did.

We are talking fahrenheit right?

 

[Elessar_94]

Now you need to know why your alarm isn't going off. That sequel you hear that I can't could be a failing horn.

Ground the tan wire with the key switch on....no sound, open up control box and hot wire horn and see if it's dead.

When I test for overheat at the first sign of going over 150...160 I shut her down.

Not sure if recommend doing what you did.

We are talking fahrenheit right?

Yes, I only tested in Fahrenheit. We didn’t drive it that much. I just did a bunch of temperature scans at once and wrote everything down. I’m going to start with the head gasket and go from there. I’ll deal with the horn later assuming I can solve the overheating issue.

 

[Mc Tool]

Have you cleaned out the tube that takes the water from the pump up to the motor . It take not much crud building up on the inside to slow down the water ( long gun cleaning kit is brilliant for this )

 

[Elessar_94]

Have you cleaned out the tube that takes the water from the pump up to the motor . It take not much crud building up on the inside to slow down the water ( long gun cleaning kit is brilliant for this )

The repair shop took care of the lower unit so I haven’t seen the condition of that tube but the motor is peeing VERY strong now so I don’t think there could be a blockage that early in the cooling circuit. If all else fails after I clean the cylinder channels I will check there next.

 

[Mc Tool]

Yes I thought about the strong pee after I posted , but cleaning out all them passages sure cant hurt .
If your using one of them IR thermometers you need to mix in a bit of common sense, they dont read well off shiny surfaces ( I have a 50 deg c difference in temp between the cast iron inside and the enamel outer )

 

[Elessar_94]

Yes I thought about the strong pee after I posted , but cleaning out all them passages sure cant hurt .
If your using one of them IR thermometers you need to mix in a bit of common sense, they dont read well off shiny surfaces ( I have a 50 deg c difference in temp between the cast iron inside and the enamel outer )

Ah, interesting. I’m using a fairly cheap $20 laser thermometer (see pic below). I just noticed that I read the instructions wrong and was using an emissivity setting meant for iron (0.70), not aluminum (0.30) so that could very well be impacting my results

I should do another test in my driveway with the correct setting dialed in. I can only idle the motor on muffs but if it looks good I’ll bring it to the lake and re-test next weekend.

 

[saltchuckmatt]

Ah, interesting. I’m using a fairly cheap $20 laser thermometer (see pic below). I just noticed that I read the instructions wrong and was using an emissivity setting meant for iron (0.70), not aluminum (0.30) so that could very well be impacting my results

I should do another test in my driveway with the correct setting dialed in. I can only idle the motor on muffs but if it looks good I’ll bring it to the lake and re-test next weekend.

Don't run that motor anymore except for short times trying to see if it is going "into" an overheat. Find out whether you have tool issues or overheat. I have a cheap Harbor Freight IR gun and it works fine.

Run motor in driveway only. Diagnose, repair then use.

 

[Elessar_94]

Alright y’all, I have removed all the cylinder head bolts - they all came out smoothly (hallelujah!) however the cylinder head is firmly stuck in place...

What is the recommended course of action to remove the stuck cylinder head? Tap it with a hammer? I’m worried I’ll break something. Dangar Marine has a video where he uses a pry bar. See photos: