Low/No Oil Alarm

[FreeBeeTony]

I have twin '95 175 Johnsons w/ the VRO connected.
In the process of de-winterization and wanted to check my Low/No Oil Alarm.
I connected pre-mixed fuel to the engine and connected a clear 1/4" ID tube to the oil intake of the pump to monitor oil consumption.
Started the engine and verified it was indeed pulling oil.....~an inch every 6-7 seconds down the hose which I believe is normal......I let the oil go dry and waited for the alarm........never came on.
Ran the same test on the other and got the same results.

Verified the alarm works by shorting out the temp sensor wire.

How long does it take for the Low/No oil alarm to sound? Is there another way to verify it's operation?

 

[GA_Boater]

How did you let the oil go dry?

 

[FreeBeeTony]

As I said I connected a clear 1/4" ID tube (~12" long) and filled it with 2-cycle oil.
Connected a separate gas tank w/ pre-mix.
Ran the motor until all the oil was used in the tube,,,,,,and even disconnected it.

FYI......the low oil alarm from the oil tank has been disconnected.

 

[GA_Boater]

The low oil alarm is in the tank.

 

[FreeBeeTony]

The low oil alarm is in the tank.

Understood..........
I'm trying to test/verify the no oil alarm in case there is a problem with NO oil getting to the engine,
How long should the engine run w/o oil connected to the pump?......while running on pre-mix.

 

[GA_Boater]

Until it runs out of gas.

 

[dingbat]

Understood..........
I'm trying to test/verify the no oil alarm in case there is a problem with NO oil getting to the engine,
How long should the engine run w/o oil connected to the pump?......while running on pre-mix.

Keep in mind that the pump is full of oil as well.

At idle, it could take quite sometime (10-15 minutes) to empty the pump and set the no oil alarm off

 

[flyingscott]

Agree it can take awhile for the oil to run out and set the alarm off. Make sure you re-prime the pumps correctly when done.

 

[FreeBeeTony]

Am I going overboard here?
Just wanted to verify the alarm rather than assume it's working.............
Any opinions?

 

[Faztbullet]

There is a low oil sensor/float in oil tank but the alarm/horn is controlled by VRO..the oil tank wire can be disconnected and it should still sound a no oil horn, just may take a couple of minutes. Make sure your running some pre-mix when testing.

 

[FreeBeeTony]

Guess I didn't run it long enough.......w/o the oil.
Maybe I will try again next w/e.......still have the pre-mix available.

 

[cfauvel]

ok in order for the no-oil alarm to work you HAVE to have a good tach pulse at the vro.
If your tach isn't working then most likely the regulator is bad, and the no-oil alarm won't work.


The VRO circuitry is counting tach pulses, at 8192 pulses it sounds the alarm, during the oil injecting the oil is channeled through a teeny tiny piston that pushes up one side of a pin , the other side othe pin presses down onto a contact and RESETS the counter.

I believe there MIGHT be some additional components in the circuit board (I thought it is was in later years though) that kind of suppresses the alarm at idle.

When I did my tests, I was told to increase the speed.

At idle the horn didn't sound after about 4 minutes, at 2000 or so it sounded in about 1.5 minutes.

testing no-oil alarm at idle
https://youtu.be/NWmdAMG7NHM

testing No-oil alarm at 2000rpm
https://youtu.be/P-b1GAphKOE

reset pin working
https://youtu.be/gV7zKuVQaD8

 

[FreeBeeTony]

I know my regulators are good and the tachs are working..........all replaced last season.
Guess I will try again this w/e and let them run longer.........
I will update.

 

[cfauvel]

I know my regulators are good and the tachs are working..........all replaced last season.
Guess I will try again this w/e and let them run longer.........
I will update.

and a tad faster than idle....

 

[Mikey N.C.]

IMHO, If you are worried about that happening and trashing a motor. Why not get rid of VRO and premix ?

 

[Mikey N.C.]

I read wrong date

 

[FreeBeeTony]

UPDATE: Ran both engines w/o the oil hose connected and the fuel intake going to a separate tank w/ pre-mix,
Both alarms came on between 3.5-4.5 min...........running between 1100-1300RPM's.
Reconnected oil hoses and alarm disappeared on both engines.
Now I feel confident in the VRO system!