What's the accurate way to check fuel level?

[Admeister]

I drained old gas from my 1990 22' classic and put 20 gallons of fresh gas in it. Fuel gauge reads near empty. Is this common? How can I check my fuel level? Or do I need a new sender/sensor? Thanks.

[Ed Donnelly]

One of the members makes a very accurate sender
Do a search for his name
Sometimes I even forget my name..Ed I think

[gcarter]

One of the members makes a very accurate sender
Do a search for his name
Sometimes I even forget my name..Ed I think

Bob Wilson...AKA "TidBart" does!

[JayZ]

I drained old gas from my 1990 22' classic and put 20 gallons of fresh gas in it. Fuel gauge reads near empty. Is this common? How can I check my fuel level? Or do I need a new sender/sensor? Thanks.


A dipstick...

[Tidbart]

A regular float sender will read near 1/2 tank with 20 gallons of fuel in 55 gallon tank. Tank being level of course. This gives you an idea of the inaccuracy of a float sender in a semi-vee style tank.

You float sender could be stuck near the bottom of the tank or just plain worn out. They don't last forever. A quick check with an ohmmeter across the disconnected sender terminals will give you an idea. 240+33=273, 273/2=136. If you ohm reading across the terminals are near 136 +/- 10%, or so then it would appear to be working. This is provided you have a 240/33 ohm setup.

I will be away this weekend, but if you need any help, I will be around next week.

In the mean time, here is some reading..... http://www.donzi.net/forums/showthread.php?62690-Tank-corrected-Fuel-Sender-for-Classics&highlight=fuel+sender

Bob

PS, my phone number is on the post if you want to call sometime.

[Morgan's Cloud]

Fill it up 'till it overflows . That's the one time you know exactly where you stand.
After that , all the rest is just guessing . :biggrin.:

[Carl C]

When the gauge starts moving or bouncing around it's time to start looking for a gas dock.

[Redink]

Bob,

I'll be calling next week. I have a 1995 22c with VDO guages. Did your test and am OK. Also will be replacing with Autometer which you list as OK. Will want one of your senders, gasket and bolts. Hopefully you still have some.

Thank you! :worthy:

Ken

[Conquistador_del_mar]

Fill it up 'till it overflows . That's the one time you know exactly where you stand.
After that , all the rest is just guessing . :biggrin.:

Yep. I have had many boats over the years, and all of them had a learning curve as to the fuel gauge readings depending on many factors - tank size, tank construction, tank placement including angle, sending gauge placement, angle of the hull when running, etc. Too many variable factors to get accurate readings compared to a fuel gauge in a vehicle that runs level with a basically rectangular tank. Most of my boats will read 1/4 tank more fuel when in the water than on the trailer due to the angle of the hull in the water. I always start to worry if the gauge reads less than 1/4 tank in any boat. My 1971 18' Donzi was almost out of fuel when reading less than 1/4 tank. I like Tidbart's logarythmic sender concept - at least it makes for a more realistic reading depending on many variables.

[Morgan's Cloud]

Bill , all of that is exactly why I don't trust electric fuel gauges . The placement and design of today's tanks no longer lends them to the old dipstick methods that I used to see on the old wooden Chris Craft types that were around when I was growing up .
You know , big ol' round or cuboid tank right under the deck with a straight piece of fill hose it was easy to get the sawn off broomstick to give a true reading.

I put manual sight gauges in all of my boats . On the St T the fwd tank is an inaccessible , gaugeless v bottomed belly tank so I wing it with that one , but the tank under the console is a basic cube so I trust that gauge .

On the Mag with its v bottomed belly tank I always remind my brother that all the fuel gauge does is tell you where the float is in relation to the bottom of the tank.
Typical of the 22C's it doesn't move too much or too quickly as long as it's in the rectangular flat section . As soon as it hits the v taper it's like 'Yikes' , head to the gas station fast !

But at least I'm not putting my trust in the questionable accuracy of an electric sending unit with it's myriad of issues.

[Ghost]

I use my fuel gauge. But as a backup I also fill the tank and reset my GPS trip odometer. Much of the time, the number of miles traveled on the tank is as useful as what the gauge reads.

[Carl C]

You will get to know your range. I can make it to Put-in-Bay from north Lake St. Clair which is about 80 miles. If running somewhat fast this leaves me with 5-10 gallons left. I pushed my luck once and the gauge went to empty as I neared the ramp. I slowed down to conserve fuel. Made it to the launch ramp. When I filled the tank it took 50 gallons! That means I was somewhere between fumes and two gallons! That's the closest I've come to running out of fuel.

[duckhunter]

Fill it up 'till it overflows . That's the one time you know exactly where you stand.
After that , all the rest is just guessing . :biggrin.:

Disagree.

A stopped clock is right twice a day. You know when it's full, and you definitely know when you just sucked the last drop out of the tank 3/4 of a mile from the ramp.

[duckhunter]

Fill it up 'till it overflows . That's the one time you know exactly where you stand.
After that , all the rest is just guessing . :biggrin.:

Disagree.

A stopped clock is right twice a day. You know when it's full, and you definitely know when you just sucked the last drop out of the tank 3/4 of a mile from the ramp. :eek:

[gcarter]

So, I found out this weekend Bob's fuel sensor is pretty darn accurate.
Several weeks ago, I put 16 gallons of fuel in the 62 gallon new, completely empty tank.
Yesterday, I hooked up the battery ground and turned on the ignition switch for the first time.
The new sensor and gauge read exactly 1/4 tank. So, it gets my approval.

[mike o]

So, I found out this weekend Bob's fuel sensor is pretty darn accurate.
Several weeks ago, I put 16 gallons of fuel in the 62 gallon new, completely empty tank.
Yesterday, I hooked up the battery ground and turned on the ignition switch for the first time.
The new sensor and gauge read exactly 1/4 tank. So, it gets my approval.

I bought one from Bob 2 yr's ago. And its the best $ I have ever spent on my 18 :cool!:

Next to my JL Audio killer sound system :kingme: Of coarse :party:

[JayZ]

Tested my gauge last night...

brilliant idea going for a moonlight cruise after a night out... Ok maybe not.

calling sea tow because you were stranded on the lake at 2:00 am. - not so great!