Low oil alarm 1989 gulfstream

[DMC43]

Does anyone know where the low oil alarm is indicated on 89 gulfstream? I was running up CT river and alarms were going off. I added a gallon to each tank ( twin Yamaha 150s) and the problem seemed to go away. How much oil does each tank hold? I can’t seem to find that info
There was plenty of oil in the fill on the engine so I’m assuming alarms are in the actual tanks

 

[glacierbaze]

Common Yamaha tank size is 2.8 gallons. If you get low on the engine tank, it will reduce rpm, and go into limp mode, at least more recent ones do.

 

[seasick]

Does anyone know where the low oil alarm is indicated on 89 gulfstream? I was running up CT river and alarms were going off. I added a gallon to each tank ( twin Yamaha 150s) and the problem seemed to go away. How much oil does each tank hold? I can’t seem to find that info
There was plenty of oil in the fill on the engine so I’m assuming alarms are in the actual tanks

There are different alarms for different conditions. When the remote tank (the big one in the locker) gets low, a yellow alarm is raised. If the oil level in the main tank (the smaller one under the cowling) gets low, a red alarm is raised and the motor will go into 'limp' mode where engine revs are limited
The oil system uses about one gallon of oil for every 50 gallons of gas burned so if you added and use 100 gallons of gas since you last added oil, you probably used 2 gallons of oil . OK, don't hold me to the math, the oil system uses different ratios for different rev ranges, so I sort of averaged the range (which varies from about 100:1 at idle to 40:1 at WOT)
If you have the Yamaha digital gauges, the oil status is on the tachometer gauge on the bottom. You may have the older gauges that have colored indications, e.g. yellow, red.

Be aware that when the remote tank oil gets really low ( empty), the level in the main tank will go down since it isn't being refilled from the remote tank. When the level gets low, you get a red alarm and that is not to be ignored nor should the motor be run with that alarm. Doing so may lead to catastrophic failure.

 

[DMC43]

thanks yeah I have the older gauges. red/yellow/green
I guess I was low on oil but when I checked it seemed to be about half full. Guess I was wrong. I cannot find any info on the size of both oil tanks and when I remove the circular cover to access oil caps, theres not enough room to see the actual tanks, without having to remove that section of the deck.
you seem knowledgable on this boat so I have another question. Ive never used the fresh water sink in the cabin and ive been trying figure out if it actually works. Someone told me it will only turn on if theres water in the tank. But I don't want to add water and then have it not work beacause id have to figure out how to pump the water out for winterization

 

[DMC43]

@ Glacierbaze, thanks. So there mustve been at least a gallon in each tank when alarm went off. I added a gallon to each oil tank and they were at least 3/4 full

 

[seasick]

The switch for the fresh water pump has to be on. If it is working, you will hear it pump for a short period and stop assuming the pump is good, there are no leaks or blockages AND there is water in the tank.
The pumps builds up pressure to a set point and then turns off. When you open a faucet, water flows and the pump will cycle to maintain pressure.
So first step is to find the switch which will be at the helm where all the other switches are. Hopefully when you turn on that switch, the pump will cycle.
Regarding the need for water in the tank: You shouldn't run the pump with an empty tank. That may overheat the pump since it won't cycle off and running dry may damage the impeller ( some pumps are listed as OK to run dry)

 

[seasick]

Regarding the oil tank: It holds about 2 3/4 gallons of oil. Open the fill cap and stick a wooden or plastic stick in it until it hits bottom. Make a not of where the stick is level with the top of the tank (less the cap flange of course).
When you pull out that stick you will see how deep the oil is. That level compared to the mark you made for the maximum depth will give you a rough idea of how much oil is in the tank.
I think that a gallon of oil raises the level about 3 inches but don't hold me to that.
Overfilling the tank makes a mess of the tank and bilge so go slow until you know how much the tank will take based on its current level. Using a funnel with a long neck helps.