Fuel Level Sight Glass Replacement?

[firstbase]

Originally Posted by jleonard

In the 14 years that I owned my boat I never looked at the sight tubes other than to make sure they weren't leaking.

I go with engine/generator hours on a spreadsheet (I use 3.6 gph as an estimate) to see where I am. However, a visual confirmation would be comforting.

[rgano]

Originally Posted by jleonard

In the 14 years that I owned my boat I never looked at the sight tubes other than to make sure they weren't leaking.

That begs the question, "Why did you never look at them?"

[tiltrider1]

Originally Posted by rgano

That begs the question, "Why did you never look at them?"

He didn’t need the accuracy. Some people have gauges and they never go below 1/4 tank, others go by hours, again never going below a 1/4 tank. I like data. My sight tubes are market in 10 gallon increments. Even though I know my fuel consumption I can verify.

[syjos]

My sight gauges are marked in 5 gallon increments and I look at them once every few days while cruising. I have found that since the sight gauges are mounted at the forward end of the fuel tanks, trim and list will cause reading inaccuracy. My fuel fills are located at the middle of the tanks and I find that taking a dip stick reading is more accurate.

I keep track of fuel usage in a logbook and enter engine hours and calculate remaining fuel. I update the fuel log every 4 hours when I switch tanks. I dip the tanks once a week while cruising and adjust the numbers in the logbook. There is a one to 5 gallon discrepancy between the logbook and dip reading. The dip stick is more accurate.

[psneeld]

Some people use engine hrs and a memorable cruise RPM to estimate fuel. Especially when you carry more fuel than you need on a monthly basis of cruising.

[rgano]

Looking at the sight gauge can reveal more information than just how much fuel is in the tank. Water might show up there. With the valves closed after checking a very low tank, opening them after filling will allow a surge into the tube showing possible bottom contaminants. If you don't have a bottom drain, disconnecting the top and bending it over to a container can give you a bottom sample. There may be a few other tricks, but these come to mind for reasons to pay attention to sight gauges.

Emptying and then refilling a tank in known, marked increments is an excellent way to end up with a usage measurement tool. I have a console tank gauge as well as a Floscan installation. It is handy to compare the Floscan to the sight gauge after a day's run at 10 GPH. And the sight gauge is where I would be looking if ever I got into a situation where fuel remaining was a critical issue.

[jleonard]

Originally Posted by rgano

That begs the question, "Why did you never look at them?"

I found my gage was very accurate. I verified it with a dowel and tape measure soon after I bought the boat.
I could “guestimate” how much fuel I could take on within 10% from reading the gage and knowing tank size.
I asked myself “why would I crawl around in the engine room just to verify fuel level? I already spend enough time in the hole”

[jleonard]

I never drained any water or crap from my multi stage filter system. At filter change time the elements always looked pretty good.
I was not in denial I just used those indicators to feel confident in my fuel quality.
Maybe I’m different that way but that’s what and why