Diesel Fuel tank gauge or lack of one

[maxxkatt]

I have a 1974 30 foot Morgan. The aft diesel fuel tank has no gauge or indicator. the tank is fiberglass and opaque and the fuel filler hose goes at 90 degree angle so cannot measure with a stick.

Any ideas on how I can determine how much fuel I have left in the tank?

John

 

[Stu Jackson]

If you know how big the tank is, fill it up and subtract the difference.

Then start keeping track of your usage and you'll know how many gallons per hour you use, and will never need a fuel gauge.

 

[higgs]

Stu's plan works until the day you motor into big head seas for many hours.

 

[maxxkatt]

more info

Another question - it is a westerbeke 20hp diesel engine. Had a diesel also on the Pearson and never ran out of fuel since it is lake sailing. Maybe I am worrying about nothing. I keep an extra 2 gallons in the aft locker so if I do run out I figure I can just pour in that two gallons and restart the engine. Is it hard to restart after you run the engine out of fuel? Are there any precautions I should take in doing this?

thanks

 

[Stu Jackson]

You should learn how to bleed your engine. When you change your filters you'll need to do so, also when you run out of fuel, which you shouldn't if you follow my suggestion. Go to www.Marinediesledirect.com, find your engine and learn how to bleed it.

 

[Deadline]

I removed the aft panel and use a flashlight to measure the tank. Works great, costs less.

 

[Gary_H]

Is there no room to install a sending unit and gauge? I'm afraid I'm not familiar with that boat or how the tank is installed.

 

[Warren Milberg]

Perhaps like Stu, I've been using a #2 pencil and a spiral notebook as my fuel guage for years. It will never let you down. Just make up a fuel consumption chart for your boat/engine at various rpms and keep track of engine hours. Big seas or little ones have little impact if you know your consumption rates for various conditions. At the end of each season, when I fill the tank for the winter, I often have found that my calculations are within .2 of gal to the actual amount needed to fill up.

 

[Stu Jackson]

Here's my fuel log: http://c34.org/bbs/index.php/topic,3841.0.html

Over 13 years I've never thought the need to figure it on conditions. Average is more than enough, 'cuz over time they, well, average out.

And I'm with Warren on this: what I project is very, very close to what I do when I refill.

1/2 gallon an hour, 10 gallons every 20 hours on a 23 gallon tank.

Simple.

And a perfect place for: YMMV. For instance, newer C34s with M35 engines use 3/4 to 1 gallon an hour compared to my 21 hp M25.

 

[Stu Jackson]

Stu's plan works until the day you motor into big head seas for many hours.

Not to be contrary, but if it's gallons per hour, it doesn't matter what the headseas may be. I run the engine at a tad over 3/4 throttle all the time anyway, 'cept for when I'm starting out or docking. And if I'm just ticking over for, for instance, cruising through the Delta, for an extended half hour or so, all it does is reduce my fuel consumption. You know, to make up for those few times I have to goose it, like trailing my son behind the boat when he said he could hold on for an extended period at over 6 knots.