A couple questions

[Tatt00z]

Hello everyone, I have a 1990 Marlin, and a couple questions. The two oil reservoir tanks on the stern, do they coincide with the 2 gas tanks, i.e.is the one closest to engines for the aux. tank?
Next question, when I bought the boat, the previous owner stated it had a main 160 gallon tank, and a 140 aux. tank. I finally ran all the gas out of the main tank, filled it back up, and it only took 95 gallons. My question is, are the gauges wrong, or is it only a 100 gallon main tank.
Thanks everyone, Glen

 

[mboyatt]

With respect to question 1, NO, the 2 oil reservoir tanks do not coincide with each fuel tank. The oil reservoir tanks each serve one of the outboards. Others please verify, but that is my understanding of how it is set up.

 

[seasick]

With respect to question 1, NO, the 2 oil reservoir tanks do not coincide with each fuel tank. The oil reservoir tanks each serve one of the outboards. Others please verify, but that is my understanding of how it is set up.

Yup, oil is mixed in the motor not the gas tank.
The original spec for the 90 Marlin was a total capacity of 306 gallons of fuel. I don;t know how the actual size of the two tanks but your 160/140 would sound about right. That said, you may have a replacement tank that is a different size.
Your tank may not have been empty. Did you run out of gas or assume based on the gauge that the tank was empty?

 

[Tatt00z]

No, didn't run out of gas, but when we were heading back in, the gauge was "flashing", that I guess meant we were getting close. So the next morning, I filled it up, and only took 94 gallons. I'm guessing if the tank is 160, approx. 70 gallons would not be "flashing" close to empty.
Any way thanks for the response, I'm really enjoying Striper fishing with my son, and in the whole scheme of things, that's all that really matters.

 

[seasick]

No, didn't run out of gas, but when we were heading back in, the gauge was "flashing", that I guess meant we were getting close. So the next morning, I filled it up, and only took 94 gallons. I'm guessing if the tank is 160, approx. 70 gallons would not be "flashing" close to empty.
Any way thanks for the response, I'm really enjoying Striper fishing with my son, and in the whole scheme of things, that's all that really matters.

The bars on the gauge can be misleading. On my boat, when two bars change to one bar, I may still have 1/4 tank. If I don't see when the two bars changed to one, I can't be sure if I am near two bars or near one flashing bar.When the one solid bar starts to flash, I have at least 1/8 tank.
You have to be careful though since the angle of the hull can greatly affect the reading. For example, on plane, I may read one solid bar but when I slow down and the bow levels off, all of a sudden the bar will be flashing. In reality, I rarely let the tank get that low.
The best approach is to use the gauge as a guideline and not an absolute indication. I pretty much know what fuel I typically burn based on trip distance and speed and I make sure I note the readings at rest.
I also have a pretty good idea of how far and how long I can sail once the one bar flashes.
Of course having an aux tank helps in that you can run out of main and not be stranded
That said, if you fill the aux, you should alternate which tank to run on and make sure that each gets refilled routinely with fresh fuel.

 

[Tucker]

When I bought my boat I was also getting weird readings. I replaced the OEM senders with WEMA units and that took care of the problem. The WEMA guys are real helpful. About the oil tanks. A guy in my marina just blew up his engine because of water in the oil tank. Strongly recommend removing the oil tanks and cleaning them out, AND replacing the O-rings on the fill caps. Are they Yamaha engines?

 

[freddy063]

the two oil tanks are one per motor, fill both at the same time, might be 2 gallons half way will take a gallon. I never had a working fuel gauge,I use the fuel ,management system it will tell you pretty close to used gallons, and it a safer way to watch your gallon per hour and end of day useage.