Low Oil Level Alarm with Full Tank...(Boscoe chim in)

[Jason2tpa]

'98 S115TLRW

Beautiful day today here in Tampa, not such a successful boat day. I experienced a low oil level alarm today followed by RPM reduction, etc. First time this engine has alarmed since I've owned it. The diagnosis would be simple if the oil level was actually low...but that would be too easy, right. Once I got the alarm I shut down, verified the remote oil tank was full which it was. Popped the cowling off and saw the engine oil tank was at the lower level mark, which is where it's always been every time I've looked in the past.

My tach doesn't have the red, yellow, green markings. But if it did, what I'm seeing on the tach during this alarm is a solid red bar, blinking yellow bar, no green bar.

Soo, where to start the diagnosis? Boscoe...I searched the threads to find some assistance and came across a similar posting as mine. Took a snap shot of your reply. I've attached a pic of your response, along with a pic of the type of tach I'm using. Quoting you, "the horn can sound a low oil alert yet the oil pump might still have sufficient oil to supply to the motor."

Since this alarm isn't truly sounding because of low tank oil, either in the remote or engine oil tanks, i'm left to assume it's an electrical issue, failed remote oil level sensor?? The low oil alarm sounds only because its detected "low oil", not a failure with the delivery system (pump). Right?

If the low oil alarm is sounding with a full oil tank, what are we talking about here as the culprit of this alarm?

[boscoe99]

The main oil tank (engine mounted) being low on oil is what causes the low oil alarm to sound. The remote tank won't do it.

You confirmed that the main tank is low. Now we need to figure out why it got that way.

Let's do a test. Remove the sump from the main tank and drain the oil into a container. Clean, reattach and secure the sump.

Make sure the remote tank is full of oil. Turn the key to the on position only. Wait just a bit. Does the electric oil pump in the remote tank come on? Does oil start to flow into the main tank? If so, wait and watch what happens. When the main tank gets to about half full the alarm should stop. Oil should continue to flow until the main tank is full or three minutes time has passed since you turned the key on.

Report back here with your findings please.

[ausnoelm]

This never gets old does it? No, hang on, yes it does, I could just put 2011 now, which must be the times this has been dealt with, explained, diagrams drawn and trouble shooting posted, now, to the OP, follow instructions, do not assume or tell them why it can't be a certain part.

[99yam40]

'98 S115TLRW

Popped the cowling off and saw the engine oil tank was at the lower level mark, which is where it's always been every time I've looked in the past.

If the low oil alarm is sounding with a full oil tank, what are we talking about here as the culprit of this alarm?

the oil level should never be at the lower mark if the system is working properly

[Jason2tpa]

The main oil tank (engine mounted) being low on oil is what causes the low oil alarm to sound. The remote tank won't do it.

You confirmed that the main tank is low. Now we need to figure out why it got that way.

I had read another one of your posts about reading the engine oil level. I attached a snap shot. Perhaps I've made a mistake. I thought if the engine oil is anywhere in between the top level mark and bottom level mark, all is ok. Yes, the engine oil was at the lower mark, as indicated in my first post. But it wasn't below. Knowing the engine oil fluctuates between the two marks, I didn't consider it "low" because it wasn't below the lower level mark.

Ok, I will test as you indicated and will report back with results.

[Jason2tpa]

the oil level should never be at the lower mark if the system is working properly

Ok, let's say the remote tank is full and the engine oil level is at the lower mark when I check it. What are we talking about then, an oil feed pump issue?

[pstephens46]

Please follow doctors orders. Interesting stuff here. At least for a four stroke owner...

[boscoe99]

I can't say precisely where the oil level will be with respect to the tank markings when the low oil alarm will sound.

There is a float in the sensor assembly that fits down into the tank. That float activates three switches. The top switch is activated when the float is coming up and gets near the top. The switch closes and sends a ground to the ECU which tells the ECU to stop sending oil to the tank.

The middle switch is closed when the float drops downward to near the middle of the tank. The switch closing tells the ECU to start transferring oil. It sends a ground to the ECU. Oil flows and fills the tank, the float rises to near the top and the top switch gets closed to stop the transfer of oil.

Normally the float will rise when oil is added, fall when oil is used, and the process repeats itself over and over without the user even knowing it is happening.

If and when the float goes down to near the bottom of the tank it will close the bottom switch. This tells the ECU to sound the alarm and to put the motor into RPM reduction mode.

Now why will the main tank get so low that the alarm sounds? Pump can fail, remote tank can get low on oil, the filter on the remote oil tank can clog, the oil hose can get crimped, wiring to and from the remote tank can become defective, etc.. Trouble shooting is needed to find the problem.

[cpostis]

The main oil tank (engine mounted) being low on oil is what causes the low oil alarm to sound. The remote tank won't do it.

You confirmed that the main tank is low. Now we need to figure out why it got that way.

Let's do a test. Remove the sump from the main tank and drain the oil into a container. Clean, reattach and secure the sump.

Make sure the remote tank is full of oil. Turn the key to the on position only. Wait just a bit. Does the electric oil pump in the remote tank come on? Does oil start to flow into the main tank? If so, wait and watch what happens. When the main tank gets to about half full the alarm should stop. Oil should continue to flow until the main tank is full or three minutes time has passed since you turned the key on.

Report back here with your findings please.

To add to this...
I had the same symptoms you have when I first got my used Yammy. My strainer on the remote tank was restricted with a "gooey" oil.
If you find that oil does not flow from the remote to the engine tank, and you can hear/feel the remote pump operating you should check the strainer circled in red in the image below between the remote tank outlet to the remote pump. You'll have to remove the remote tank from the holding bracket to get to it. Probably a good idea to clean your tank and replace the strainer anyway seeing that it is probably well over 15 years old. Clean your strainer in the engine tank and check/replace the little round gasket at the bottom of the level sensor as well.

[Jason2tpa]

I can't say precisely where the oil level will be with respect to the tank markings when the low oil alarm will sound.

There is a float in the sensor assembly that fits down into the tank. That float activates three switches. The top switch is activated when the float is coming up and gets near the top. The switch closes and sends a ground to the ECU which tells the ECU to stop sending oil to the tank.

The middle switch is closed when the float drops downward to near the middle of the tank. The switch closing tells the ECU to start transferring oil. It sends a ground to the ECU. Oil flows and fills the tank, the float rises to near the top and the top switch gets closed to stop the transfer of oil.

Normally the float will rise when oil is added, fall when oil is used, and the process repeats itself over and over without the user even knowing it is happening.

If and when the float goes down to near the bottom of the tank it will close the bottom switch. This tells the ECU to sound the alarm and to put the motor into RPM reduction mode.

Now why will the main tank get so low that the alarm sounds? Pump can fail, remote tank can get low on oil, the filter on the remote oil tank can clog, the oil hose can get crimped, wiring to and from the remote tank can become defective, etc.. Trouble shooting is needed to find the problem.

Greatly appreciate the detailed explanation. I'll get over to the boat this week and start trouble shooting. Will let you know the outcome.

[Jason2tpa]

To add to this...
I had the same symptoms you have when I first got my used Yammy. My strainer on the remote tank was restricted with a "gooey" oil.
If you find that oil does not flow from the remote to the engine tank, and you can hear/feel the remote pump operating you should check the strainer circled in red in the image below between the remote tank outlet to the remote pump. You'll have to remove the remote tank from the holding bracket to get to it. Probably a good idea to clean your tank and replace the strainer anyway seeing that it is probably well over 15 years old. Clean your strainer in the engine tank and check/replace the little round gasket at the bottom of the level sensor as well.

Excellent suggestion, thanks. I'll check this strainer while trouble shooting.

[rodbolt17]

I cannot believe we still beat this dead horse.
it must be rotten by now.
like Boscoe said.
simply drain the engine tank via the water trap.
reinstall the vynil tube.
turn the key on.
tank should refill and the transfer pump turn off in 180 seconds or less.

if the pump fails to turn on you have a 180 second window to do some multimeter checks.

if the pump turns on and transfer does not shut off and the engine tank refilled in less than 180 seconds go find the restriction.
typically it will be that well maintained remote oil tank filter.

[Jason2tpa]

Update:

Drained the main tank, secured sump back onto tank. Turned key to ON position. No filling whatsoever. Placed my hand on the reserve tanks pump and couldn't feel anything. Rodbolt mentioned a multimeter test. Please advise those steps. I assume what's needed to be checked is if power is getting to the pump to rule out an electrical issue or pump failure issue. Ive got an orange wite and blue wire coming off the square plastic wire gang port. Those two wires connect to the corresponding colored wired pigtail stemming from reserve tank pump.

[Jason2tpa]

Forgot to mention this...after learning the main tank wasn't filling, while the key remained in the ON position I flipped on the emergency pump switch. It's technical name is the Control Unit Assy, located under the engines main tank.

This also did not feed oil into the main tank. I haven't found the wiring diagram for that accessory, so i'm not sure how its powered and/or if its power source is the same as the remote tanks power supply.

Thought this extra info would be of some use for your advice. Thanks.

[99yam40]

you really need to have a service manual for your motor.

Or do some searching on line for info, just need to make sure it matches up with your motor.

This has been cover too many times for you not to find info on troubleshooting .
see if you have power to the motor and then see if the ground is being provided to it by the bypass switch or oil con*****er