175hp blackmax 1987 oil alarm

[jigmister]

the oil alarm on my outboard has been beeping the last few trips out at certian times.
At first it would beep a few times when I would hit a wake. Then it started beeping when the boat would come offf plane. Commmon sense told me it was the oil sloshing around in the oil tank on top of the engine.
I made sure the tank was full and went on my way.

Now the alram is consistant. It sounds anytime I put the boat in neutral for any amount of time.

come off pad, idle slowly in the no wake without any problem. put her in "N" to stop and the alarm sounds.
Put her back in gear and she is quiet.
Whats going on?

I am reading the factory manual tonight to see what I can learn.

Thanks for any help

 

[oldman570]

Re: 175hp blackmax 1987 oil alarm

Think you might have a wire that is getting shorted in the control or in the motor to get a meter andstart testing for a short at the conector plug to see if you can get it to short out while moving the control. Manual should have wireing diagrams for motor and control.
Oldman570

 

[bajaunderground]

Re: 175hp blackmax 1987 oil alarm

Get rid of tank and associated alarm...then premix!

 

[aussieflash]

Re: 175hp blackmax 1987 oil alarm

What "Oldman" said.Sounds like bad connection in control box.Could also be a spark issue on one or more cylinders.
One coil lead to switch box has green sensor/module alarm wire connected.If that cylinder is dropping off the alarm will sound.I had this problem and unfortunately it was a bad switch box.

 

[jigmister]

Re: 175hp blackmax 1987 oil alarm

Thank you everyone for the good words.
I have read the manual and searched on here. Now I have a good understanding as how the system works.
Checked all the wiring and grounds. Now the problem has become intermittent again. It will not hit on alarm when at home on the garden hose. On the water it never hit all day long until the last stop I made.
I am consdering a new oil module but I see they are a bit expensive. CDI site says its no longer available and merc wants 225 bones.

I will post what path I choose.

 

[SparkieBoat]

Re: 175hp blackmax 1987 oil alarm

go premix..just had this problem with another 86 150 xr2. here is what I did.
all you need to do is reroute your fuel line from the oil pump connection directly to where fuel comes into the cowl, I had to twist the fuel fitting with a 9/16 wrench so it did not kink the fuel line, I also had to cut about 2 inchs off the fuel line so it would not interfere with the linkage, ( I had to reroute the fuel line in front of the linkage and kinda tuck it in between the 2 bottom carbs.) this will by pass your oil pump. just behind your oil pump there is a rectangle box that has some wires going into it, (from your oil tank sensor) this box has a large blue wire going to the block as a ground, remove the screw and disconnect this ground, then tape it up so it will not ground, I used a zip tie to hold it to the wire harness, be sure to reconnect the other wires grounded there. BE SURE TO PREMIX YOUR FUEL AND PUMP THE PREMIXED FUEL THROUGH YOUR FUEL LINE BEFORE RESTARTING YOUR MOTOR. (your fuel line will be filled with unmixed fuel unless you do this) Also test your over heat alarm, on the right side or your motor (from behind) there is a wire going from the top/center of your head (your overheat sensor) to a post with a couple other wires, turn on your key then ground that post (I used a screw driver across the block then touch the post) it should buzz.

 

[jigmister]

Re: 175hp blackmax 1987 oil alarm

thanks for the words sparkyboat. I am going to try an alarm module and if that dose not solve it I will premix.

I also noticed a dribble of water coming from the lower part of the powerhead where I am learn is an exhaust gasket and plate?
Is this a problem? Dose this gasket go out? when it dose what problems dose it create?
Thanks

 

[SparkieBoat]

Re: 175hp blackmax 1987 oil alarm

if you run fresh water, it will probably be ok..if you run in salt water you will need to fix it. only real problem would be corrosion, at least that I can think of.

 

[aussieflash]

Re: 175hp blackmax 1987 oil alarm

So you tested the module and it was faulty?Or are you just buying and hoping.Check spark.

 

[jigmister]

Re: 175hp blackmax 1987 oil alarm

did some testing. With the engine idling and the alram sounding I unpluged the module wires one by one. The alarm continued to sound.
Tested the oil float with ohm meter. came back as it should. Checked the switch boxes and coils with DVA tester on my fluke meter. All came back well.
Of course the alram sounds intermitently. It was not sounding at any time I did the DVA testing. Last fishing trip out it never once sounded all day long.

I am grasping for straws with the module purchase because I have not prooved it bad.
I have a tournamet this weekend. If I want to play it safe and premix the oil, what ratio and where to get a mix cup? manual says it runs 100:1 at idle and 50:1 at WOT. seems like if I mix 50:1 I will have a smoke out at idle. 100:1 and I burn up the engine.

 

[SparkieBoat]

Re: 175hp blackmax 1987 oil alarm

too much oil will not hurt at all..I would continue to premix until you are sure your problem is resolved. you should premix at 50:1 you can plug off the oil pump if you want..and disconnect the ground wire I mentioned in post #6 to stop the alarm.

 

[jigmister]

Re: 175hp blackmax 1987 oil alarm

thanks for the words. Got the alarm module and installed today. Will test boat tommrow and sunday. Old module has some pretty old weatherd looking wires. May have been the problem.

 

[jigmister]

Re: 175hp blackmax 1987 oil alarm

well tested the new module out and the problem still exsits. This time I was able to interupt the alarm by unpluging the purple wire.
Upon the wire schematic I find that the purple wire is 12 V power. where this power wire comes from is yet to be found.

any ideas whats wrong? Dose this finding mean that the alarm is false and not a loss of oil?

 

[17rogue70]

Re: 175hp blackmax 1987 oil alarm

could be the tank sensor (cap) on the engine or the sensor at the oil pump on top. i just pulled mine off too. thanks to sparkies directions on here . really easy and is foolproof. the only way it can malfunction is if you dont put any oil in it. i did it because i didnt know the history of my engine, (new to me) and had sat for a few years. it was all operational when removed, but i feel more comfortable now , knowing the age of my engine.

 

[SparkieBoat]

Re: 175hp blackmax 1987 oil alarm

it could be the box that your sensor wires run to..warning module assembly..I am not sure how to test it..cause I just chunk them. BTW I could not find a 175 for 1987, there is one in 1988 ,you may want to check your year again.

 

[jigmister]

Re: 175hp blackmax 1987 oil alarm

the boat is 87. The motor actauly says 86.

Alarm only sounds at idle in N

With alarm sounding I unpluged the purple wire. alarm stops. Comes back when purple wire is plugged back in.
Purple wire runs up to IGN switch according to wire schematic. (power wire)

anyone know what I should try next?

 

[aussieflash]

Re: 175hp blackmax 1987 oil alarm

Think we have the same service manual as mine is a 88 V6.I'll do more investigations as I now remember my mechanic unplugged my purple wire, saying it was only the warning beep at start up that's playing up????I know my oil pump is working by the blue smoke at start up.

 

[jigmister]

Re: 175hp blackmax 1987 oil alarm

the boat is 87. The motor actauly says 86.

Alarm only sounds at idle in N

With alarm sounding I unpluged the purple wire. alarm stops. Comes back when purple wire is plugged back in.
Purple wire runs up to IGN switch according to wire schematic. (power wire)

anyone know what I should try next?

anyone else?

 

[oldman570]

Re: 175hp blackmax 1987 oil alarm

From what you has stated and looking at a wireing diagram for your motor, I would look at the temp sender and unplug it to see if it is causing the problem. If it dose then I would think that either that sensor or the water pump impeller needs to be looked at. the pump might be pumping enough when the motor is reved up from idle or there could be restictions in the cooling system that would cause the motor to go into alarm. If this is a salt water motor, and hasn't been flushed after use, the salt will harden in the cooling system and cause a restiction.

 

[CharlieB]

Re: 175hp blackmax 1987 oil alarm

A slightly flooding carb at an idle can foul a plug, setting off the oil alarm, yet clear as soon as engine speed increases.

Check the green wire on the oil module running back to on of the ignition coils, usually but not always #4. Once you know which cyl, trim the motor level, remove the airbox cover, while holding pressure on the primer bulb carefully watch that carb throat for fuel leaking.

Also check that cyl's trigger wire, disconnect the throttle cable, dva test cranking while S L O W L Y moving the throttle/timing lever from idle to WOT and back. A broken yet abutted wire in a trigger can fire the cyl and also fail as the wires are flexed.

Lastly, inspect that cyl's spark plug, is it excessively cleaner than the others? A leaking exhaust gasket or cracked exhaust divider may allow water to enter the cyl and cause a misfire at an idle. This one is really clutching at straws, highly unlikely but you always have to look at your plugs to see what's going on.