HELP, Johnson 90hp warning horn

[NZjohnson90]

I have a 1984 Johnson 90 V4 VRO.

We have only had the motor for about 10 hours but have never had any issues, bought it from a marine shop who checked it all out and said although they wont guarantee it because of age but it is all good even compressions (110 if i remember correctly) etc. they had sold the motor a few years ago and had done all the maintenance since.

I had a full service done just for piece of mind about 4 hours ago, the mechanic told me the impeller was already new and it has had very recent new head gaskets etc. He replaced all the seals etc and said he couldn't see any issues with it either.

So yesterday took the boat to the river for the first time (usually go on the lakes), less than 5 mins in and the warning horn starts beeping rapidly. I turn the motor off instantly, leave it for a min and start it up again, slightly worried as we are drifting rapidly downstream from the ramp. The motor starts fine and runs perfect again for about 2 or 3 mins then the beeper again, so we turn off instantly, wait a min starts up fine again for 2 or 3 mins. This happens 1 more time and we make it back to the ramp on the 4th go before the beeper goes off.

Things that could could be a factor......
1. Before we went I started the boat on the drive with the muffs on of course, just to make sure we were all good before we left. I ran it for about 20 mins to warm it up, no worries and it all ran perfect, good strong water flow and telltale. No warning noises. I am worried to start it again on the muffs at home until I get some advice in case it has damaged the impeller or something.

2. The road to the river is heavily corrugated dirt road so despite driving slow the boat got quite a shaking. Could it have damaged a sensor or something?

3. The river has a fair amount of weed and was quite silty compared to the lake. I doubt it could be this because there were several other boats out with no worries and we did not appear to collect any weed on the way. But... maybe?

The VRO tank is half full and the hoses did not seem to be kinked or anything.

Sorry I have waffled on a bit again, but I wanted to give as much info as possible. I really don't have to cash to spend on this at the moment and don't want to take it back to the mechanic again. Any ideas of things to check are much appreciated.

Thanks

 

[emdsapmgr]

Re: HELP, Johnson 90hp warning horn

Your owner's manual should indicate the warning signals from the control box. A constant horn should indicate either a critical fault with the VRO pump, or an overheat of the powerhead. An intermittent beeping should indicate a low oil warning in the oil tank. You may have a defective oil sensor in the tank (if the tank is really half full), or you could have a problem with the horn itself. A low oil warning can sound if the tank is 1/4 full or less.

 

[NZjohnson90]

Re: HELP, Johnson 90hp warning horn

Hey, thanks for the reply. I don't have a manual, If I could find one I would snap it up though.

So It sounds non critical which is good. I'll give it a go on the muffs when the rain stops and see what I can find out. The tank is definitely over half full, but it is also the lowest it has been since I had the boat so it could have always been like that for all I know.

Anyone any ideas on how to trouble shoot the tank sensor or horn?

 

[emdsapmgr]

Re: HELP, Johnson 90hp warning horn

You may want to invest in a factory service manual for your engine. Contact Ken Cook Co., in Milwaukee, or they are on the web.

 

[Brew2]

Re: HELP, Johnson 90hp warning horn

Identifying the warning horn signal will be a first step. Do a search here on the forum for something like "warning horn" and I'm sure you'll find a post detailing the various signals. Going by memory, the rapid beep is the engine overheat warning.

Could be as simple as a stuck thermostat, or damaged impeller. Also could be a flakey sensor as they can often bite the dust (my oil tank sensor did). As someone said, track down and buy a manual to go through trouble shooting options. Generic Seloc manual will be a lot better than nothing and can be found almost anywhere (I bought one at Wal-Mart). OEM one is definitely better...can often be found on Ebay.

Good luck!

 

[rodbolt]

Re: HELP, Johnson 90hp warning horn

over the years the horn duration has changed slightly but as a general rule, steady tone is overheat.
1/2 second tone every 1/2 second is NO OIL in the VRO. water in the VRO tank,lines and pump can create this as well.
1/2 second tone every 30 seconds is low remote tank level.

 

[bob johnson]

Re: HELP, Johnson 90hp warning horn

I know some guys dont like to hear this...but if it were me... id go back to the ramp, leave the boat on the trailer but back it down into the water, start the motor and let it warm up....maybe 20 minutes like you did in your driveway.

then put the motor in gear and run the rpms up to maybe 2000....and let it stay like that until you get that horn again...

you could then check the heads with your hands to see if they are blistering hot or just warm or somewhere in between...

i dont think you want to go full WOT, because you may not get enough water to the intake sitting on the trailer..

but 2000 rpms might be ok.

some guys dont like this because of the issues it can cause for dirt and gravel ramps, causing wash out that trailer then fall victim to.

if you have a deep paved ramp, you wont cause any problems

this way you have a better testing bed that the driveway, but wont get caught stranded out in the river..

and you arent replying on ahose to supply you water..

plus if it runs good with no alarm you can take it and run laps right in front of the ramp at wot!!


how long did you let the alarm sound before you shut it down?

the reason i ask is on my control and motor 1995 115hp johnson, the horn sounds at the exact same 2 minute interval everytime i start the motor and exactly 10 seconds later it shuts off.....no matter what

I have temp senders in each head and a water pressure gauge...

I have never found and answer to the horn issue, but just ignore it now, that i have taken the boat out about 2 dozen times now.

good luck

bob

 

[Brew2]

Re: HELP, Johnson 90hp warning horn

Almost forgot....if you want to find out which sensor is resulting in the alarm you can disconnect each sensor lead one by one as the alarm is sounding and see which one stops the alarm.

The sensor leads I believe are all tan wires that have a scissor connection (close to the block, oil tank, and VRO pump) that is hidden by a black rubber sleeve. You should be able to peel back the sleeve to expose each connection point. Be sure to expose each connection prior to starting the motor so you don't have to keep it running very long with the alarm sounding.

Good luck!

 

[NZjohnson90]

Re: HELP, Johnson 90hp warning horn

Thanks for all the help guys, will hopefully get out and investigate further tomorrow.

The two questions I still need to clear up are...

Is rapid beep beep beep (like mine is doing) overheat, or is continuous beeeeeeep overheat. I had a good search on here and nobody seems to have a definitive answer.

Secondly I really want to run the motor to get to the bottom of the problem. Would it be unwise to run the outboard on the hose, if it is a damaged impeller this is the only thing I can think of which could have damaged it. I don't want to cause any more problems for myself.

Unfortunately the only ramp near us is the rive which is a busy single ramp so I can't really block it up for an engine test...

Had a good look around for manuals, seem very hard to come by (bear in mind im in NZ, not quite the resources here that there are in the states). There are a few kicking around on Trademe (nz ebay), but not for my engine and all $80plus.

 

[emdsapmgr]

Re: HELP, Johnson 90hp warning horn

Rodbolt is correct on the factory warning horns for the engine. For some reason on my 92, when the tank gets low, I get a constant horn, not the normal beeping one every 30 seconds.... So, you need to carefully check to see what is really going on with yours in case your horn is acting up. In case that this horn is a valid oil warning, indicating you have an oiling issue, I'd add oil (at 50:1 ratio) into the fuel tank of the boat. That way, when you run the engine during your diagnosis period, you are assured of proper oil. [the worst that will happen is that you will over-oil for that tankful of gas.] I'd run the engine, then when the horn sounds, disconnect the oil tank sensor wire and see what happens.

 

[OneLuv1979]

Re: HELP, Johnson 90hp warning horn

Does the motor shake ?

I had a similar problem but my motor would loose power and start shaking ...
I would pump the primer bulb and it would pick back up ...

Ended up being a faulty fuel pump / VRO , took it off myself and brought it to the local johnson service dealer and he rebuilt it for $40 , boat has not skipped a beat since ...

 

[nymack66]

Re: HELP, Johnson 90hp warning horn

What was the water flow out the engine like? Strong or none at all?
Make sure the VRO oil line is primed (squeeze the primer)
It could be a stuck thermostat or vro be careful pre-mix until you resolve it.
Check out this site find your make/model and observe every diagram you will learn a great deal about your engine http://shop2.evinrude.com

 

[NZjohnson90]

Re: HELP, Johnson 90hp warning horn

What was the water flow out the engine like? Strong or none at all?
Make sure the VRO oil line is primed (squeeze the primer)
It could be a stuck thermostat or vro be careful pre-mix until you resolve it.
Check out this site find your make/model and observe every diagram you will learn a great deal about your engine http://shop2.evinrude.com

Thanks nymack, found that site last night, saved it to my bookmarks - very useful.

Feel like I am getting somewhere now, the motor was pumping water good n strong as always which leads me to believe VRO problem as many people on here have suggested.

Have just spoken to a local marine mechanic who did the service for me and he confirmed what you just said also. He said to premix oil 50:1 but still keep the VRO connected and give the bulb a good squeeze as the motor is running to unblock any airlocks, draw a line on the VRO bottle and run a good tote tank or so of premixed fuel through and see if the VRO bottle has gone down at all. That way I get to test the VRO system without risk of blowing the motor, even though it would be double-oiling it should give me my answer.

Will keep you guys posted on the results, pretty simple test and hopefully should help some of you guys out with the same problem in future.

THANK GOD I DIDN"T RUN THE MOTOR ON THE MUFFS LAST NIGHT AS I WAS GOING TO, WITHOUT PREMIX!!!

If it turns out to be VRO problem I just dissconnect the system.

 

[NZjohnson90]

Re: HELP, Johnson 90hp warning horn

Oh, 1 last question, how do I disconnect the VRO horn so it does not drive me crazy while I test.

Note I DO still want to overheat alarm to work just in case!

 

[NZjohnson90]

Re: HELP, Johnson 90hp warning horn

OK, latest update, I did as emdsapmgr, nymack66 and my mechanic suggested and premixed 10litres of fuel. Gave it a good 20 min run on the driveway with the muffs.

Before I started I gave the VRO a prime and the tank/primer bulb gurgled - hmmm unusual as it doesn't usually do that. The motor started pretty much first turn as always and sounded perfect. 5 mins in and beep beep beep, I gave the VRO bulb a pump and the horn instantly stopped, 5 more mins beep beep beep, another pump and the horn stops again. Runs perfect for the next 10 mins.....

Had to call it a day at that as my neighbors won't appreciate the sound of my V4 at dusk.

SO the verdict - my guess is either

Air leak somewhere in the VRO hose.
VRO hose walls collapsed - it does look like it could do with replacing.
Faulty VRO pump.

I could replace the hose and try again, but that could be $50 of wasted time.
Or I could just scrap the VRO, disconnect the horn and premix from now on - I am leaning towards this at the moment for future piece of mind - I can't afford an engine rebuild right now!!

 

[NZjohnson90]

Re: HELP, Johnson 90hp warning horn

Also when I first started up on tickover the revs were about 1000rpm (don't seem to need the throttle to start). after about 5 mins they crept up to 1500rpm, 5 mins later settled at about 1200rpm for the rest of the time - is this normal?

The telltale is totally cold but water from the exhaust and outlets was just warm is this normal?

Lastly STUPID QUESTION but I just wanna make sure 200ml oil to 10litres fuel?

 

[emdsapmgr]

Re: HELP, Johnson 90hp warning horn

When your engine is cold, the rpm's are different than when the engine reaches normal operating temps. I would say your rpm's while idling on the trailer are pretty typical. These don't mean much, as the rpm's at rest-floating in the water are the ones that count. If you disconnect at the horn due to the VRO issue, you will loose the horn for overheats. Look to disconnect any wiring at the VRO or the oil tank, to keep the overheat sensors connected. I wouldn't worry about the water temps, also pretty normal. If you can borrow a laser temp gun, shoot it at the heads, should be in the 145-155 degree F. range. The incoming lower unit cooling water goes into the exhaust cover first, then through the rest of the powerhead. Fuel and oil hoses can go bad with time-can leak air or fuel or the ball valves in the bulb can go bad, esp if the fuel hose is old and not made to handle today's ethanol fuels. The oil hose is a special size (1/4"), with the yellow stripe. Not a big expense. Your engine has a clearish oil filter just under the pump. The 86 models have a clear tube (sight glass) so that you can see if the oil is being sucked up through the system with no air bubbles. Keep an eye on it to see if the pump is able to keep oil sucked constantly to the pump. If the plastic glass/filter is not always colored fully with the oil, you may have a weak pump or you may be sucking in air. Priming either the fuel or the oil hose, and having the horn quit is suspect. Something is leaking or weak.

 

[bob johnson]

Re: HELP, Johnson 90hp warning horn

so to get some facts straight

the oil horn can sound even when the oil tank is full?

if not then where is the trip for the oil alarm?? someplace on the combo fuel pump

if you dissconnect the wireing harness from the oil tank, does that PREVENT you from ever getting an oil alarm

is there a PUMP in the oil tank?

or is the oil pump just part of the FUEL pump?

bob

 

[nymack66]

Re: HELP, Johnson 90hp warning horn

I will not recommend you disconnect the VRO just yet, If its a defective pump then yes this will be an option.
There is also a filter/screen in the VRO pickup tube make sure its not clog, if not then it will not hurt replacing the complete hose and primer bulb.
Your pre-mix should be 50:1 Please see this link for the correct petrol ratio
http://www.csgnetwork.com/oilfuelcalc.html
Here is nice write up on the VRO
http://continuouswave.com/whaler/reference/VRO.html
Must read http://continuouswave.com/whaler/reference/OMCvMERC.html
Complete index here ..
http://continuouswave.com/whaler/reference/



Good Luck and keep us posted

 

[NZjohnson90]

Re: HELP, Johnson 90hp warning horn

I will not recommend you disconnect the VRO just yet, If its a defective pump then yes this will be an option.
There is also a filter/screen in the VRO pickup tube make sure its not clog, if not then it will not hurt replacing the complete hose and primer bulb.
Your pre-mix should be 50:1 Please see this link for the correct petrol ratio
http://www.csgnetwork.com/oilfuelcalc.html
Here is nice write up on the VRO
http://continuouswave.com/whaler/reference/VRO.html
Must read http://continuouswave.com/whaler/reference/OMCvMERC.html
Complete index here ..
http://continuouswave.com/whaler/reference/



Good Luck and keep us posted

Absolutely brilliant write ups on the VRO and Merc systems, more people should read those thanks for that. I feel like I have a much better understanding of how it all works and much more confidence in trying to sort it out.

After reading that I would now say 99% sure that the problem is a simple air leak in the hose system somewhere and that should be a simple fix.

It seems though the early pumps 84-85 were prone to failure, but after reading the article it also appears for some reason I have a later model pump despite the motor being an 84. Also if the pump was failing it would not be pumping fuel either and would not start.

It could be a clogged pickup I guess but that looks like it requires dismantling the tank to find out. So I'll try replacing the hose first.

I am moving house this week and have to get the wheel bearings changed on the trailer and also wanna do some glass repairs on the keel (which I'm about to start a new thread on) so for the time being I will keep premixing and let you know what happens in future with the oil.

Thanks so much with all your help everyone.

Oh and the last piece of vital info I picked up from the articles for anyone reading this is the VRO tanks can be susceptible to water intrusion from condensation. WORTH CHECKING FOR PIECE OF MIND!