VRO2 pump warning alarm

[bernschu]

During warmup at the launch ramp, my 1985 Evinrude V4 90 hp sounded the alarm horn in a manner that I had not previously heard. It was different from the alarm sound for a low oil reservior or a hot engine. The alarm started shortly after startup and continued while the engine was running. The alarm was intermittent with approximately 0.5 sec on and 1 sec off periods. I verified that the oil reservior was not low and the engine was not over heated.
In 1994 I replaced the original VRO pump with a 4 wire VRO2 pump. Of course, my 1985 service manual does not cover the alarm function of the new pump. What does the alarm mean? I can see from the harness connections that the pump is monitoring the engine tach.
During subsequent fresh water flushing on the trailer, the horn again sounded while the idling exhaust smoke appeared to be about normal.
Help!

[boats.net]

Unfortunately we do not have the service manual for this particular motor. However on a 1985 there are not many options that can sound the alarm. Over Heating, Low oil and possibly Low voltage.

[coueytwo]

Thats the NO OIL Alarm. you need to purge your oil system to remove all air from the system, remove the oil hose from the vro2, pump the oil primer bulb,allow a small amount of oil to come from the oil hose , then reconnect the oil line to the VRO2..Then pump oil until you see it at the site tube... mix your boat gas at 50 to 1, so you can run you motor to check your vro oil use and check the NO OIL Alarm system.

[bernschu]

Could the NO OIL alarm also mean a malfinctioning pump, requiring replacement? I don't see how air could have gotten into the oil system unless there is a cracked oil hose somewhere. Also, what if the filter in the oil feed hose is restricted? Does anyone know what physical properties are being monitored inside the VRO2 pump? I think the tach signal is just used to determine when the engine is running.

Could a related incident have any bearing on this problem : During a fresh water flushing of the engine prior to the alarm incident, I had forgotten to reconnect the fuel line, so the engine ran on the residual fuel in the carbs and pumped excess oil into the carbs which then sat idle for a month. This then caused very hard starting and a lot of exhaust smoke before the alarm came on. Seems like there might be a cause/effect relationship triggering a temporary false NO OIL alarm.

Thanks for your inputs

[boats.net]

After purging oil system, if alarm doesn't go off or if VRO not pumping oil then VRO needs to be replaced.

[larwat]

vro horn

Is it possible problem is in remote. Mine was doing same thing and I found wire in remote was grounding. Leave engine off, turn key on, and move shift, throttle, and fast idle lever to see if it will sound horn