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VRO pump

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NitroB

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I have a '91 115hp Evinrude, not sure if the vro pump is working. I get warning horn sounds off and on. Sometimes when I start it and a few minutes later the horn will sound, and sometimes I won't get a warning horn. How can I test to see if the vro pump is pumping oil on the water hose. How can I tell if it's a faulty warning signal.
 
Install a new one... Cheaper than a power head.

Hook a premixed fuel tank at 50:1 to your engine or premix your boat fuel tank while testing to prevent damage.

Once you premix the fuel, pull the oil line off of the VRO pump and raise the rpm to about 1800 and wait, the alarm should sound after a few....

If the alarm does not sound after a short period of time, replace the pump. If the alarm sounds hook the oil line back up, mark the level in the oil tank and take the boat for a ride. After a good run you should see the oil level in the tank go down.

Make sure you have no leaks on the fuel and oil lines feeding the engine. When I say leaks I mean make sure it is not sucking air.

@1500 rpm you should be able to feel the VRO cycle approximately every eight seconds. If it takes longer or is cycling very fast...Change the pump.

Again if the pump is old and/or you squeezed the oil primer very hard...Replace the pump.
 
Run with 50:1 in your fuel tank until you sort this out.----The factory manual has the test procedure for the pump.-----The pump is elegantly simple to take apart for inspection / repair.-----I believe you might want to look at the filter in the oil tank too.-----They are an expensive pump for what they do.
 
As a reference, I ran the above mentioned VRO test on my 90 Evinrude 150hp. The NO OIL Alarm went off exactly 3 min after disconnecting the oil line. Then, the alarm went away about 20 seconds AFTER reconnecting the oil line.
 
I hope to run it at the lake this week and see if my alarm goes off and I have oil mixed in the gas just in case the alarm does go off and to see if oil goes down in the oil tank. I've also been told it could have air in the line and give a false warning alarm.
 
??-----If you have air in the oil supply line to the pump you might get the alarm.-----That would not be a ---" false alarm " -----as you stated.
 
So if there is air in the lines it would just be the regular alarm and not a false alarm? Would it keep giving the alarm until all the air is out of the lines?
 
Which warning are you receiving?

Every other second....... Every 20 or 40 seconds....... Constant and steady sounding?

If simply air in the line due to disconnecting a oil line or whatever, the VRO would require priming as follows:
********************
(Priming The VRO Pump)
(J. Reeves)

When hooking up or installing a VRO whether it is a new or original VRO pump, it must be primed in order to dispel any air that might be in the oil line.

Have the Oil line attached to the engine fitting BUT detached from the VRO. Add a piece of fuel hose if necessary to the oil line so that it can be aimed into some sort of container.

Pump the oil primer bulb, catching the oil flowing out of the line into the container until you are absolutely sure that you have rid the oil line of every bit of air that might have been trapped there.

Now, connect the oil line to the VRO and secure it. When the oil line is secured, apply pressure to the oil primer bulb ONE TIME only. That's it.
********************
If after priming properly, the "No Oil" alarm (every other second) is still encountered, and it goes off when the oil primer bulb is compressed... BUT... comes back on shortly thereafter, the VRO requires either rebuilding or replacing.
 
Sorry for the late reply Joe, I've been out of town. The warning goes off every other second and when I barely squeeze the primer bulb it goes off and will stay off for 3-5 minutes then will come back on and did so 2 or 3 times till I squeezed the bulb. I think I will go through the test again that you said to purge the air through the lines to see if that stops the warning, I didn't do that the first time.
 
Get the correct manusl for your motor. It will have the instructions for testing and bleeding the Vro. I hope you are running pre-mix in that motor.
 
Get the correct manual for your motor. It will have the instructions for testing and bleeding the Vro. I hope you are running pre-mix in that motor.
 
NitroB said:
Sorry for the late reply Joe, I've been out of town. The warning goes off every other second and when I barely squeeze the primer bulb it goes off and will stay off for 3-5 minutes then will come back on and did so 2 or 3 times till I squeezed the bulb. I think I will go through the test again that you said to purge the air through the lines to see if that stops the warning, I didn't do that the first time.
Click to expand...

Yeah... That's the route to take. If after going thru the "priming" routine properly, that "every other second" alarm still exists.... Rebuild or replace that VRO.
 
If your still getting oil alarm after purge... replace VRO/OMS pump as you cannot rebuild the oil side only the fuel/air motor side.
 
I ran the motor on the hose again with the oil line disconnected from the pump and got the warning sounds after a minute or so. I shut off the engine and hooked the clear hose with half inch marks on it for three inches total, filled with oil to the top mark. I ran the engine at idle speed and it showed it was taking two inches of oil in bout 5min, after the first half inch was taken the alarm would sound but t was still taking oil. I disconnect the clear hose and squeezed all the air out of the oil line, 8oz of oil out. I hooked the oil line back up to the pump and squeezed the bulb one time, started engine, ran for 6 minutes no alarm. Shut it off for 10min then started back up and run for 2min alarm went off and I barely squeezed the bulb I mean barely and the alarm turned off. It did it twice and the alarm would turn off, could be faulty alarm. Can I keep running pre mix in the tank and disconnect the oil line from the pump and plug the oil lines and just use the pump for a fuel pump and not use the oil side and disconnect the wires from the oil side. Can I change to a straight fuel pump omc #438559 and just pre mix my gas.
 
There is a spot on the intake manifold to mount a pump with fuel in and fuel out hose.---The pump mounts directly over the pulse port with 2 screws ( 10-24 ) and a gasket.----That pulse port now has a plug that must be removed.----Remove the pulse limiter for the VRO and plug that port.
 
Thanks racer, didn't know there was a spot on the intake for the pump to mount to. Would that be pump #438556 with fuel line in and out and the #438559 pump has a pulse port on it where you use the pulse limiter hose already there if you use that one. Could I still use the fuel pump side of the vro and disconnect the oil side of it?
 
The 438556 is the one that mounts directly to the intake manifold.----As you may know that pump was used on the 88 HP version of your motor.------Those 88 HP model left the factory without VRO oil injection.----And yes it will pump plentuy of fuel to run the 115 HP models.-----The choice on how to run your motor is yours.----As you see there are options.
 
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