1990 E90TLESB 90 HP outboard no oil sensor horn goes off even though the system is working. WHY?!

[tolent]

1990 E90TLESB 90 HP outboard no oil sensor horn goes off even though the system is working. WHY?!

I have a 1990 90 HP Evinrude outboard with VRO. It runs fine both fuel and oil levels are topped off but when I run the warm up the horn that tells me the system is not getting oil goes off. A short blast every 20 secs or so. I know that the system works because I monitored the oil level in tank and it lowers as it should and there is smoke out the exhaust. If the system is working Ok, why does the horn go off telling me there is no oil when I know there is?

 

[Joe Reeves]

The warning horn beeping every 20 seconds or so is NOT telling you there is NO oil.... it is warning you that the oil level is down to 1/4 tank.
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(VRO Horn Warnings)
(J. Reeves)

NOTE: I retired around 1991/92. Possibly some of the later V4 engines and others may also incorporate a fuel vacuum switch that would enable a fuel restriction warning to sound as mentioned below, an unknown factor to myself.

1 - A steady constant beep = Overheating - The V/6 engines, possibly some others, have a fuel restriction warning which is also a steady constant beep.

2 - A beep every 20 or 40 seconds = oil level has dropped to 1/4 tank. (Late model engine = Every 40 seconds)

3 - A beep every other second = VRO failure, air leak in oil line, oil restriction, (anything that would result in a lack of oil being supplied to the engine).

NOTE - If the warning horn is the black plastic (overpriced) three wire type horn, the warning horn should beep once when the ignition key is turned to the ON position. If it does not, it is either faulty or someone has disconnected it (a stupid move!). At any rate, if it does not beep which indicates that the horn is non functional, find out why and do not run the engine until the problem is corrected.
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