V6 OMC 'NO OIL ALARM' won't sound - troubleshooting help wanted

[at100plus]

1987 225 Evinrude. I have run the engine several times now on premix. I have twins. The starboard engine started sounding the no oil alarm after about 3 to 5 mins of running but the port motor won't sound the alarm. I have run it up to about 8 mins on the muffs. I wanted to verify it was working before I bleed the oil line and connect it to the VRO pump.

Note: It chirps the alarm when I turn on the key and the tan wire grounded DOES sound the overheat alarm and I have put a continuity tester on the tan wire as it makes its way thru the red amphenol cable to the VRO pump and also out of the small black plug up to the top of the engine somewhere under the flywheel. I checked and cleaned all related ground wires.

I think all wiring is good, it must be a sensor or module that detects the no oil condition?? Perhaps I'm just not running it long enough?

If I can't figure it out, the boat is going in the water Saturday I figure I'll run it on premix for like up to a half hour and see if it goes off before I connect the oil line.

[Lockjaw]

Be sure to bleed the oil line before you connect it. Then run premix too and verify its pulling oil. You can do a test with a clear hose at idle and make sure the pump is pulsing and pulling oil by filling just the hose, after you mark off increments of 1 inch.

On my eagle motor, it will detect no oil in a hurry. I can't remember what the pump looks like on the 90 degree looper motors though. Sorry.

I'd also make sure, if you haven't, that you clean out the oil tank thoroughly and refill with fresh oil. Then pump bulb and bleed it and make sure you have good oil flow.

[perfmarine1]

That's about right, half of those systems don't work. That is why we all mix, we are smarter than a VRO system. Nearly everyone that comes in for a rebuild, and it looks like VRO problem, they always say no buzzer.

[at100plus]

That's about right, half of those systems don't work. That is why we all mix, we are smarter than a VRO system. Nearly everyone that comes in for a rebuild, and it looks like VRO problem, they always say no buzzer.

Yea I put new oil in, new filters and gaskets in the oil tanks too. I would premix but I'm sharing the boat with my dad he he doesn't want to deal with that. I did bleed the starboard motor good and it's smoking more now that I connected the line. Also the alarm stopped sounding on that one so it should be good to go. I also did mark the level on the tanks. I'd just feel better if I knew the motor detects no oil condition before putting straight gas in.

[at100plus]

http://continuouswave.com/whaler/reference/VRO.html

This article made me feel a bit more confident with keeping VRO. I just want to make sure the alarm works first.

[perfmarine1]

Caution, if the VRO is so good why was OMC replacing blocks by the 10 of thousands for customers with VRO problems? I know of at least 15 that they replaced, some of them a year or two out of warranty. I still say it is what put them under. That combined with the fitch disaster. If you knew how many Vro systems, while unhooking them, I found solid water in the line you would never use it. Same problem with all oil injection systems, CONDENSATION, people refuse too keep them full.

[at100plus]

Caution, if the VRO is so good why was OMC replacing blocks by the 10 of thousands for customers with VRO problems? I know of at least 15 that they replaced, some of them a year or two out of warranty. I still say it is what put them under. That combined with the fitch disaster. If you knew how many Vro systems, while unhooking them, I found solid water in the line you would never use it. Same problem with all oil injection systems, CONDENSATION, people refuse too keep them full.

Not really looking to start a oil injection versus premix debate as I am already on the side of premix. I'm just looking for an answer as to what detects a no oil condition and how do I test it. The VRO has to stay on these motors it's not really my decision.

[racer]

Sensor in the pump. Do you have the new version pump with 4 wires? If so make sure the purple wire has power. Thru the years I have seen a lot of issues blamed on vro pumps when they were not the issue. You do need to make sure the tanks are clean and remember the vent in the tank will allow water in. I have seen pumps blamed for a burnt piston but if only one is hurt and the others are good it was not the cross since it mixes oil before any cylinder gets fuel. Of course I have seen engines that the cross was to b lame for failure.

[at100plus]

[perfmarine1]

So what you are saying is when you unhook the oil line at the VRO and run at 1000rpm's you never get the alarm. 2 sec on 2sec off? On one motor only? If that is the plug in the last pic, you have old style pump, 3 wire.

[at100plus]

Correct on my port motor alarm won't sound. Starboard motor alarm works.

[at100plus]

In the pics I posted there's a purple from the harness that connects to a white wire under the manual primer (red lever).

2nd pic I have no idea what the gray thing is but it has 2 wires coming off of it. One went to ground, I have to double check I can't remember where the other went. I want to say that went to a ground too which I thought was odd but it's like that on my other motor too.

3rd pic shows the tan wire from the engine harness, it goes to the oil tank wire. The other side of the oil tank wire goes to a ground.

Last pic shows the plug that the tan wire goes thru and then up to the top. The tan wire has continuity all the way from key to buzzer to this plug to the top of the motor.

I've tried googling for a wire diagram but nothing ever shows much more detail than tan wire goes out to VRO.

Again these are 1987 motors so this should be a VRO2 system. It has the brown fuel outlet.

[perfmarine1]

Tan wire is horn, black wire is ground, gray is tach wire. If all wires Confirmed good replace VRO.

[perfmarine1]

Does that purple hooked to primer go into vro? it should not. Gray thing in 2nd pic is fuel vacume sensor,if you get a restriction in fuel line to fuel tank the buzzer will sound. Vac sensor has nothing to do with VRO, it should have ground wire and tan. All tan wires are hooked together and go to buzzer. Each buzzer component has a different buzzer tone.

[at100plus]

I'm trying to figure out why the alarm system won't detect that the oil tank isn't connected. I have no reason to suspect the oil side of the VRO2 isn't working yet. Certainly the fuel pump side works great. At this point it's either electrical or I haven't run it long enough to burn the oil that remained in the pump I think. These motors were in storage since about 2001. I ran them both first time this past November on the flush muffs and 3 times on the muffs since on premix with oil line disconnected. Total run time since coming out of storage is about 10-15 mins.