Continuous alarm sounding Johnson 115 "79

[loveeverybody]

Drove wot, alarm sounded, for the first time. Not sure what this means on this motor? Is there anyone out there that has an Heads, Up sure would appreciate it,Thanks! Also this motor ran fine, until I drove it into A sandbar.
Initially I thought sand ,debris; were suck in the lower unit. After this brilliant
moment, I put in reverse only to notice it was less power,not as smooth and
water pouring over the transom. It was a change on how it performed in reverse! In forward gear it ran just fine. I pushed it to wot, heard the alarm
sound, and backed off the throtle , the alarm ceased. All day no alarm sound
even at higher speed. So I thought, maybe if something got sucked in; it had worked itself out. pulling the boat out of the water I noticed what look like Dirty oil or exhaust all over the lower unit just below the cowl. Once again a first with this engine; Maybe to much oil in gas mixture? Anyway got home ran it with muffs
alarm sounded on start up ; this has never happend before. So I took off the cowl and followed the harness from the control box to the red plug wiggled it a little bit started it up no alarm. engine idles fine runs great and strong. Checked the gear oil GOOD! Well I hope with disclosing these symptoms will
enable you guys out there to figure this one out. Thanks Again!

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

If the screens at the water intake on the lower unit were in good condition, the only thing that should have entered the water pump was fine sand. That sand would have then been pumped into the cooling circuit and possible could have blocked the thermostats or part of the thermostat circuit.

You could disconnect the large hoses at the bases of the cylinder heads and backflush the engines cooling circuits. You could drop the lower unit and make sure the water pump impeller is still in good shape. You could clean out the thermostat housing.

When a temperature switch closes and sounds the overheat alarm you are already at high enough heat to distort cylinder heads and blow cylinder head gaskets. Good shop practice is to replace the head gaskets when this has happened.

 

[loveeverybody]

Re: Continuous alarm sounding Johnson 115 "79

First, Thank you Ezeke for your knowledge on this subject. 1. My intake
screens on lower unit were shot before entering that sandbar. 2. The two waterholes below the cowling shows only the right side of water emerging
not the left; pee hole water streaming fine. Once again it ran strong after the date with the sandbar in forward gear. So I hope there is no internal damage eg.cylinder head. 3. I will backflush the hoses at the cylinder heads first. hopefully this will work, 4.Will you be kind enough to give me sort of a step by step in doing the thermostat housing cleaning? Thank you 5. Does the water coming out of the the right hole only under the cowling not the left
present a clue? 6, Tempted to drop lower unit an put a new impellar although
I just installed this one. But I guess it could easily be ruined if sand or debris got in there. 7. When running with muffs I saw water seeping out where the lower unit breaks away then little bit of oil gas or exhaust seepage but soon went away; then water continued this has nevr happend before is this perhaps another clue? Thanks again Guys for all your input!

 

[Joe Reeves]

Re: Continuous alarm sounding Johnson 115 "79

You're due for a new water pump assembly, not just an impeller, and new thermostats and bypass valve assemblies, also a new water intake screen.

With the thermostats and housing removed along with the lower unit, use the garden hose on the water tube to flush the cooling system out.

The head bolt torque is 18 to 20 foot pounds in the following sequence.

9...10
5....6
1....2
4....3
8....7

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

I did not know that your water screen (OEM PN 323466) was bad, so you will have to replace that. It requires that you drop the gearcase and remove the water pump. Without that screen, large particles will eventually enter that will do major damage.

I use Sierra Kit 18-3673 from iboats for the thermostat system; it has all the gaskets thermostats etc for the job. It would be a good idea to have it on hand before starting the work. http://www.iboats.com/mall/partfind...gd_poid=111072&gd_row=43&**********=718851243

You should also replace the 4 water deflectors while working on the cylinder heads.

Be sure that the large rubber gasket called the exhaust housing seal is in place at the base of your inner exhaust housing where it fits into the top of the gearcase.

 

[loveeverybody]

Re: Continuous alarm sounding Johnson 115 "79

Thank you both for the diagnoses. I appreciate it! Still have a question, what is
exactly wrong. Are these remedies troubleshooting ideas eg. fix what could be wrong until all is well, or do each of the remedies point to an exact symptoms I mentioned earlier. 1. No water emerging on left hole under cowling with muffs. 2. seepage of water where lower unit breaks away when using muffs. 3.continuous alarm sound intermittently bad sensor?

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

You have two temperature switches, one in each cylinder head. The switches almost never go bad, so the safe bet is that they are good and that at least one side of your engine is not getting enough cooling water.

The water is first pumped into the engine's cooling passages and then flows out according to the state of the thermostats. Any water not flowing through the engine simply bypasses the engine. So if anything blocks the thermostats (and it does not take much) the cooling water does not flow through the engine, and it overheats.

In my opinion the necessary things are the replacement of the water screen and examination of the water pump & thermostat sytems. If it were my motor I would do everything, but I have the time to do that.

 

[d.boat]

Re: Continuous alarm sounding Johnson 115 "79

Is there any chance this engine has a newer fuel pump w/ a fuel restriction alarm?

The reason I ask is that the symptoms sound a lot like a fuel restriction that maybe resolved itself:

"pushed it to wot, heard the alarm sound, and backed off the throtle, the alarm ceased. All day no alarm sound even at higher speed."

To OP: on newer engines, a constant alarm can indicate two things: overheat and fuel restriction. The difference is that fuel restriction alarm goes away soon after you reduce RPMs (thus reducing fuel need), while the overheat alarm does not. A fuel restriction can be temporary caused by something clogging the fuel intake tube in the tank, and when it falls off, the fuel is unrestricted again.

Another reason I ask is that even though the engine seems to be prior to the time when fuel pumps had a fuel restriction alarm, I once had a similar vintage outboard (80? 82?) that had been rebuilt and a more modern fuel pump had been used and it indeed gave me a fuel restriction alarm, which confused me at first.

I've boat in sandy and silty rivers and been on sandbars and shallow sandy and silty water many times, and I've never had that sort of material significantly clog water passages quickly. It's always been more of a build up type thing, not caused by a single incident.

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

Even if it had the OMS, it would not be a constant alarm on a V4. The v4 did not have a vacuum switch with constant alarm, that's a V6 feature and is not actually part of the VRO/OMS fuel pump.

There is no reason that you could not add the VRO2 or OMS to a 1979 V4 if you wanted it.

I think that the reason the motor has/had a problem was because the water intake screen was bad.

 

[loveeverybody]

Re: Continuous alarm sounding Johnson 115 "79

Thanks Ezeke for the analogy! it makes complete sense. D.Boat Thank you
for your thoughts on fuel restrictions. Its not a new fuel pump. Ezeke how difficult, and how much time required to do the inspection you suggested? Thanks again Guys for all your Positive Feedback!

 

[loveeverybody]

Re: Continuous alarm sounding Johnson 115 "79

Joe thanks for the head bolt Torque and sequence!

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

If you have done the water pump before, you will be able to estimate the time to take it off and get it back together so that you can put a new screen in place. If you just lever it up and get the broken one out, the new screen will snap in place in seconds. The delay will be cleaning the area up and making sure the drain hole at the bottom of the screen is clear so give the screen replacement itself 15 minutes max. Add how long you need to hook up a hose to the water tube and flush the engine the way Mr. Reeves suggested.

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

I am not so anal that I don't cut corners, so I always cut the belly pan to get to the thermostats on the older crossflows. If you do that you can replace the whole thermostat system in < 30 minutes and then it is much easier and quicker the next time. If the thermostat system has never been opened, your guess is as good as mine. I just seal up the cut in the belly pan with black epoxy and sand it smooth before it fully hardens.

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

New head gaskets could be $15/per and you have to have a torque wrench to put everything back. If the bolts come out OK, clean up the heads, check the water deflectors, +/- 1 hour including clean up. You need a way to test the heads and a tool to clean the mating surfaces.

You have to have all of the parts and tools at hand or allow time to get them, which is why you often are better off to pay the wrench.

A good running 79 115 is probably worth $500 off the boat, so it is hard to justify the $500 you would probably pay to have the job done right until you consider the alternative of rigging and replacing with a new equivalent motor. Check it out.

 

[d.boat]

Re: Continuous alarm sounding Johnson 115 "79

Even if it had the OMS, it would not be a constant alarm on a V4. The v4 did not have a vacuum switch with constant alarm, that's a V6 feature and is not actually part of the VRO/OMS fuel pump.

There is no reason that you could not add the VRO2 or OMS to a 1979 V4 if you wanted it.

I think that the reason the motor has/had a problem was because the water intake screen was bad.

Aha! Thanks. Yes, mine was a V6

 

[loveeverybody]

Re: Continuous alarm sounding Johnson 115 "79

Hi everybody, once again, credit to Ezeke with the correct analogy. I ran the
the motor with muffs today felt the power head one side cool the other very hot. I guess when I was on the water, I only felt one side of the Power head
Big mistake! Now I know to check both sides! Ezeke was right the sensor was good! Now that I know the left side is not cooling, Ezeke should I replace both thermostats? what do you guys suggest? Its amazing that one side can
seem normal even with P hole and still one side Hot! Thanks Again Guys For all of your help.

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

I would get the Sierra thermostat kit and replace all of the parts. You usually need at least the gaskets. There is a good possibility that you will find all 1979 vintage parts in that housing.

I would at least do the cylinder head gasket and water deflectors on the hot side.

If you find any rubber particles in the thermostat housing, you will probably find that the source is the water pump impeller.

 

[loveeverybody]

Re: Continuous alarm sounding Johnson 115 "79

Thanks so much Ezeke for everything. correct me if I'm wrong but the thermostat housing is on top of the motor on this one behind the stator,
a littlte under the fly wheel or is this the water passages ?

 

[loveeverybody]

Re: Continuous alarm sounding Johnson 115 "79

Well my last question, where the thermostats are located ;idicated Im winging this one without a shop manual. My last outboard engine was black max merc 150. I did a lot of wrenching on that one myself with the manual.
Nevertheless I have located the thermostats remove them and pulled quite a bit of sand & debris from the housing and around the adjacent parts. Cleaned up nice!
Ready for Installation.Purchased all new parts springs gaskets thermostats ect.. Problem, no manual .Is there anyone out there that can tell me Which direction the thermostats face, when going back into the housing. Upon dissasembleing the thermostats fell into the cowling no way for me to see the direction in which they are to be installed.. Much appreiciate the heads up guys! Peace

 

[ezeke]

Re: Continuous alarm sounding Johnson 115 "79

Click the thumbnail, please:

Also check this quote from forum expert member Emdsapmgr: http://forums.iboats.com/showpost.php?p=816305&postcount=3​