1991 120 VRO V4 "buzzes" at low RPMs

[ilovekingfish]

Like the title, I have a 91 120 V4 with the VRO disconnected and I run premix. I bought the boat with no oil tank, and the PO never unhooked the wires for the alarm/oil sensor. So after some research, I unhooked the wires to get it out of "limp" mode. I took it out this past weekend, and, not at first, but after about 30 minutes, I heard a quiet but noticeable "buzz" sound coming from the engine area, almost like an alarm, even though I disconnected the alarm for low/no oil. Is there another alarm on these engines, or am I simply hearing perhaps a resonance vibration or maybe just one of the line fittings rubbing against the splash well? It only happened when I was cruising at just below plane speeds, and wasn't loud enough that I instantly recognized it as an alarm.

 

[jakedaawg]

The alarm buzzer is either in the side mount control or under the dash if properly rigged.

When you first turn the key to the on position you should heer a beep. Is that the same noise?

 

[ilovekingfish]

The control housing does beep when I turn the key to ON, this buzzing is coming from back either near or from the engine. I thought it might just be a fitting rubbing or vibrating at a certain frequency. But if the oil alarm should come from the dash or Control box, then I guess it's something just rattling or vibrating around. Thanks.