1990 Yamaha Pro v 150

What would cause a solid tone or alarm on this thing? It just started today and as soon as we get up on pad or idle the alarm hits. Is the solid alarm oil, water or over heating, or maybe time to replace water separator?

Checked the oil reservoir on the motor, it's about 2/3 low, wound this be the cause?

Solid tone means overheating.

Overheating, sounds like a water pump change or the thermostats aren't opening up

All alarms on your Yamy are solid tone. Oil should be up to the upper mark on the motor mounted reservoir. Activate the switch there to put oil into this reservoir. If oil does not go in or goes real slow check the inline filter on the oil line out of the main tank. #6 here: http://www.boats.net/parts/search/Yamaha/Outboard/1990/150ETLD/OIL%20TANK/parts.html The way you are explaining the alarm it does sound like the water pump impeller. The fuel water separator will not set off an alarm on this Yamy

We are still peeing a very solid stream out of the [censored] hole. I also found some fresh oil coming off the port head. The starboard side was bone dry. I pulled all 6 plugs and yes they need to be replaced.