Mercury 40hp oil injector Beeeep

I purchased a 1995 Bass Tracker with a 95 Mercury Tracker 40hp 2 cycle 4 cylinder motor with oil injection. While redoing several things I noticed the wire to the beeper for the oil was cut, so I reconnected it. ( nothing sounded at this time) I decided to put fresh oil in the tank and check the beeper and when I did the beeper makes the continuous Beeeeeeeeeeeep. I have read several things about the beep on the web and have checked what I can. The float in oil tank reads resistance when all the way down and open when all the way up. I disconnected one and both wires from the oil tank censor and the one brown wire above the top spark plug- (water temp- I think). I mixed a tank and ran the motor with hose from the oil pump off and oil dripped out at different rates with different rpm’s.
Any ideas on anything else to try or do I need to just start mixing in the tank. Thanks for any help.

It is not uncommon to find an older motor with the "OIL LEVEL" sensor discontinued. They broke frequently and many saw them as costly to repair.

Since it's sole function in life was to tell you whether or not there was oil in the tank, and NOT if the oil injection was working, many that broke were simply disconnected.

When it comes to oil injection there is really only two predominant views - either you love/trust it or hate it/don't trust it.

I'm on the side of trust it so I personally would do everything possible to 1) make sure it's working and then 2) use it and 3) repair it if it's a variable rate pump so that it could be used.

Some oil pumps are "variable rate", so sometimes 50:1, 100:1 or points in between. On THIS model the pump is simply a 50:1 so it's more of a "convenience" (it mixes for you) so in this particular case I would not go the cost of a new pump (250'ish bucks just for the pump part) if it is not working properly - not enough advantage.

With a graduated cylinder/test tube (anything that can measure in cc's) you can test the flow of the oil pump.

Flow specifications are as follows:
660 RPM = 25.6 cc ± 10% in 30 min.
1500 RPM = 20.2 cc ± 10% in 10 min.
2500 RPM = 33.6 cc ± 10% in 10 min.
5500 RPM = 74.2 cc ± 10% in 10 min.

DO run premix until you are certain the oil pump is working properly and is hooked up.

IF you will sleep better at night by bypassing the oil system you can do that too and run pre-mix. If you choose this option post a question about how to bypass - you need to do that "correctly" as well to alleviate future problems - you shouldn't simply leave it "unhooked".

Aside from the Auto-Blend system there is very few guys/gals that work on outboards that can honestly say they have seen an oil pump that failed and fried a motor - most motors fail due to lack of waterpump service, blocked/dirty carbs, "forgetting" to add oil to the gas.

If you decide to keep the oil injection I personally still wouldn't be in a rush to fix the alarm. If you top off the tank before you take it out you should never have an issue. A FULL tank of oil will last 7 hours running at wide open throttle on this model. More than enough to last even the most active day on the water. If you can remember to mix oil with gas in a pre-mix, you certainly can remember to put oil in a tank without having an "idiot alarm" to tell you that it's low.

Thanks for the info. I think the level sensor and pump are working. Today I took the oil warning module loose and tapped on it and the beep did stop for a little while but did start back after I mounted it back on. Is the module a common problem? Is it worth repairing($120)? Does this also warn of overheating? Should I just cut the wire, fill the tank and go fishing. Thanks Chris

If it's the module itself then it is also the alarm for the "overheat".

That is important enough to replace, don't want to clog your water intake and fry your motor because it's not cooling properly.