Help... 75hp Mercury 2 stroke alarm keeps going off

[Ponyboy1995]

I have a 1994 Bass Tracker with a 75hp mercury 2 stroke. Took it out last weekend & it ran great. Out for several hours fishing. On the way back in to the dock I ran her hard & fast trying to use some old fuel. When I slowed down to idle a constant beeping alarm came on so I shut it down. After about 5 min or so of trying to figure it out I started it back up & after a minute or so I came back on. This week I changed out the thermostat & the impeller. I started it last night & after about a min or 2 the alarm started going off again. The stream coming from the pee hole was not hot & the engine was not hot to the touch. I am at a loss. The only other thing I did recently was change the plugs. It calls for NGK but the shop said they no longer make that plug & gave me autolite plugs. I don't think plugs would cause an overheat alarm but I could be wrong. What should i do next? I am at a loss.

[R2Tracker]

Oil injection tank full?... Nephew's 150 Black Max of similar age had a bad float sensor on the engine mounted oil tank. Just throwing it out there.

[Topwater 2]

The float in the tank could be oil logged causing your alarm. Does the alarm come on when you turn the key to the on position? If so, unplug the alarm wire to the tank and see if the alarm stops. I ended up unplugging that wire and just kept an eye on the tank, keep it full.

[Crappie Bob]

I believe the oil tank sensor goes off immediately when you turn on the key, not after it runs a minute or two. My oil tank float went bad like that, I removed it and glued the magnet back to the float and works like new again.