1982 Johnson 50 Sea Horse - Constant Beep While Accelerating

[Elessar_94]

Hey all,

I’m diving into the world of outboard motors for the first time here with a new-to-me 1982 Johnson 50 Sea Horse which I absolutely love, however, I have started to notice a constant beep coming from (I think?) the motor itself as I’m cruising down the lake. The beep stops when I decelerate. Thought it was my fish finder at first but it was powered off today and I still heard the beep. The engine is peeing and I do NOT have a VRO system (I mix the oil 50:1 with ethanol-free gas).

What things can I check to narrow down this problem? So far, I suspect a faulty thermostat, low gear oil (haven’t done the lower unit oil yet), possibly a weak impeller (but it’s peeing) or maybe my engine really is overheating and I’m lucky it’s still running. I’m truly lost. Any ideas?

 

[saltchuckmatt]

Could be overheat but usually comes from the remote control or under the dash.

Could be a bad sensor or impeller, thermostat....the list goes on. You need to start the test procedure and go from there. I would start by removing the gearcase and look at the pump.

Do you have any info on this motor in regards to its maintenance?

 

[racerone]

Compression test.----Post the actual values.----Blown head gasket can cause overheating,---Easy to do.-----Or ground in wiring harness setting off the alarm.-----You should have installed a new impeller when you bought this motor.

 

[Crosbyman]

peeing just tells you the impeller is pushing water up the engine and out.. the cyl jacket cooling itself is thermostat controlled so any malfunction would not stop the peeing ....yet an overheat condition could still exist .
(BTW is this a salt or fresh water engine?)
since this a new to you engine why not pull the thermostat and check it or just replace it after a possible 42 years of service,. ...along with your new impeller !

see basic concept on older engines

 

[Elessar_94]

Thanks all for the advice and recommendations.

Unfortunately I don’t know any history on the maintenance, but I was told when purchasing a couple weeks ago that there was 140 psi in both cylinders. Haven’t confirmed that myself yet though. This is a freshwater engine, however, it’s from Florida so I’m sure it’s been used in saltwater before. The previous owner preferred to keep it in freshwater too.

Will be starting with the thermostat and impeller/water pump system and go from there!

 

[Elessar_94]

Compression test.----Post the actual values.----Blown head gasket can cause overheating,---Easy to do.-----Or ground in wiring harness setting off the alarm.-----You should have installed a new impeller when you bought this motor.

I was told 140 psi in each cylinder a couple weeks ago when I bought it. I am going to be replacing the impeller ASAP - this is all VERY new to me. Can you please elaborate on the ‘ground in wiring harness’ portion? How would I go about testing this?

Between the ignition coils and power pack there is an electrical bus of some kind and I know the two tan cables coming from each cylinder are supposed to be temp sensors. I’m new to this and don’t want to misidentify parts. How would I verify if there is a faulty ground wire?

 

[Elessar_94]

peeing just tells you the impeller is pushing water up the engine and out.. the cyl jacket cooling itself is thermostat controlled so any malfunction would not stop the peeing ....yet an overheat condition could still exist .
(BTW is this a salt or fresh water engine?)
since this a new to you engine why not pull the thermostat and check it or just replace it after a possible 42 years of service,. ...along with your new impeller !

see basic concept on older engines

Thank you so much for the documentation - sadly I think our engine is the version where the thermostat is buried at the bottom of the cylinder head and not easy to reach. But I’ll get ‘er done and report back once I have the replacement thermostat in hand!

 

[racerone]

The water coming from the tell tale ---DOES NOT---circulate through the engine.----It tells you that water pump is working.----It does not mean that engine is cooling properly.----The overheat sensor goes to ground to sound the alarm.----If there is a bare wire somewhere the horn could sound.----open up the control box and have a look.

 

[cyclops222]

Sure sounds like a stuck thermostat.

 

[Crosbyman]

sure sounds like op needs to read up on OB maintenance which is the plan I guess.

btw low oil in the gear case won't give you a buzzer if that is what was suspected.

How would I verify if there is a faulty ground wire? likelkely no need to check... if it was touching the engine frame it would buzz all the time !

 

[saltchuckmatt]

Yes, agreed. Low water flow at high speeds is the most likely issue but could be many things.

Do not take this fine motor out until you discover the problem.

 

[Elessar_94]

sure sounds like op needs to read up on OB maintenance which is the plan I guess.

btw low oil in the gear case won't give you a buzzer if that is what was suspected.

How would I verify if there is a faulty ground wire? likelkely no need to check... if it was touching the engine frame it would buzz all the time !

Yes, like I’ve said numerous times now this is all brand new to me. First boat, first motor. I am a novice trying to learn multiple systems at once. Not having much luck finding the manual for this particular motor but I’ll keep looking.

 

[Elessar_94]

Sure sounds like a stuck thermostat.

Hoping it’s that! I’m working on getting to the thermostat now.

 

[racerone]

Poppit valve should open at full throttle for increased water flow.-----Inspect that item.-----That motor was the same for many years.----A factory manual from 1980 to 1988 will suffice.----Best read some books.----Many new owners have learned about motors through an empty wallet.-----Mistakes are expensive if you need to run to a shop for help.

 

[Elessar_94]

Appreciate it. I will certainly start gathering manuals and parts catalogs.

 

[racerone]

Your location??

 

[Crosbyman]

click on the small enveloppe on top corner for a private message .
visit utubes lots of good videos on yours or similar models usually

 

[saltchuckmatt]

Decent video of what you might need to do.

Not sure if id thread chase with a drill motor though.

 

[Elessar_94]

UPDATE: I managed to get the thermostat out and aside from being dirty it looks OK. I’m going to replace it anyway. Also going to replace the temp switch and gasket while I have the cylinder head off. Will report back next week when all the parts are in.

Everyone’s assistance has been super helpful and I’m very grateful to this community

 

[Elessar_94]

Your location??

South Carolina, not far from Augusta GA.