I've been having an issue with a steady "Beep-Beep" alarm on my '96 Merc 150 XRI...It started out intermittent, mostly when hitting the gas getting on plane it would beep a couple times. Now the alarm goes off constantly at idle and goes away at higher RPM. I've replaced the remote oil tank cap and checked all oil lines as well as the main tank and pick up screen. As far as I can tell the oil consumption from the main tank seems normal, but I've been adding oil to the gas just to be safe. The engine cold starts great, but takes a few turns of the key to get it going after it has warmed up. It also runs like a scaled ape at WOT.

I'm starting to think the alarm is being triggered due to some sort of timing/fuel enrichment issue. I was messing around with it today and unplugged this sensor in the picture below. I checked the connection then immediately plugged it back in. When I went to restart the engine it would NOT start. This is immediately after the engine was starting and running great. I don't know what this part is, but I'm thinking it may have something to do with my issue. Anybody have an idea what this part is and know a good way to troubleshoot it? It's located under the fuel filter on the starboard side of the engine.

That is the tps sensor, won't give an alarm, Tlw, or Mr Purdy can answer your question, I think multiple beeps is oil related and solid beep is water related,

Most likely the remote oil tank, low oil level, or float stuck or bad,

Yes that is the TPS. That year is bad about shearing the oil pump drive gear or the cap sensor going bad. First check to make sure that the motor mounted oil tank is getting full. Then check the oil sender in that oil tank by disconnecting the ground (black wire out of sensor cap)beeping stops its bad. Finally check the oil pump by loosening the bleed screw. If oil comes out the pump is working. All of these checks are done while motor is running. When in doubt, remove all of the oil injection and premix.

I've done all these steps already, including replacing the remote tank cap sensor. I'm not worried about the oil pump drive gear because I'm running an aftermarket oil injection system (Marine Solutions). I've been premixing as well, just to be safe.

After further research I'm starting to think this may be caused by a bad stator. I recently had to replace a voltage regulator because my tach stopped working. There were a couple yellow wires going into that regulator from the stator that were melted together. I repaired them and put new bullet connectors on them and that fixed my tach issue. Could a low/high voltage situation trigger this alarm I'm getting if in fact the stator is bad? I saw a video on how to ohm out the stator I'm going to check it tomorrow.

tha "only things" that trips alarm buzzer are bad oiler module, oil (low or rotation), water in tha fuel, heat (heat is a solid, constant beep)... tha heat is completely separate, jus uses tha same buzzer.. ona stock oiler motor.. don't don't know a thing 'bout your aftermarket deal.. on tha starboard side of fuel injection there is a screw on filter with water sensor at tha bottom.. unplug it..

jus unpluggin' tha tps and pluggin' it back in should not of effected tha start n run....

Does it have a water separater filter my alarm was going off changed it and it stopped mine is 2003 efi