Decathlon Fuel Tank Dipstick

jartlip

New member
Does anyone know of a fuel guage stick that is calibrated for an 8KCAB? Or has anyone made their own fuel stick?

I have one for a C172 but it isn't even close.

Thanks...Jim
 
I had the same problem, so I made my own,
Buy a school type wooden ruler and paint it with primer so the fuel level will show.
Drain tanks to empty and add fuel in 10 litre, or I guess 2 or 3 US gallon increments. I needed to put about 15 litres/4USG per side before the dipstick showed any fuel at all, and mate my first mark at 20 litres (3.8 US gallons per litre).
I continued in 10 litre additions, marking with a felt marker at each point, til the tanks were full.

The stick was inserted vertically against the back of the filler neck.

After a few weeks when I was sure I had an accurate dipstick, I had a friend make a copy from aluminium with markings engraved.

Now I am confident as I know exactly what fuel I have when I start up.

Remember to subtract the unusable fuel to get fuel available. I use 6 litres per side, the flight manual/maint manual/POH were not consistent on this so I erred on the safe side.

To get max flight fuel, remember to put in the gallon you will burn on taxi and takeoff, you will still be below MTOW when you get airborne. I find this helpful as range is a limitation with two people.

Regards

John Kempton
 
Does the Decathlon have the same size fuel tank as the 7GCBC? 36 US gallons? Could we just use your measurements if someone gets the same type of wooden ruler?

Bruno
 
The 8kcab (mine is 1977) has 20USG a side. You could calibrate the ruler for any tank by using the gradual fill procedure. My ruler is a little over 12 inches long, about 9 inches go into the tank vertically before it touches bottom. Don't drop it, or better still attach a cross piece at the top.

JK
 
FYI-

KISS, the best fuel dipstick is an unpainted paint stirrer, the fuel will immediately show when dipped and evaporate in moments to dip the opposite tank.

Bruno better to calibrate your own, in addition to a different quantity the 8KCAB tank is designed and built totally different than a 7 series, and there are design and quantity varations within the 7 series, even within the same model. The cearly tanks were 40 gal, the later ones 36 gal. And then you must always insert it the same way.

Tom-
 
Another factor between the 7's and 8's is wing dihedral angle.
Here's my dipstick info to get you going - as said above you need to do your own calibration. Mine is intended to be a little conservative but could be errors as I've converted from mm and litres to inches and USGals. Usable fuel.
I did this during the regular (every 3 years) official calibration of the gauges.
For an 8KCAB:
Bottom of stick = 3.5 Gals
2" = 9
4" = 14.5
5.8" = 19.6

NB: revised figures 4 Oct '05
 
Come to think of it, my ruler was a paint stirrer. Two for a dollar. You make your own markings for a given amount of fuel.

jk
 
Thanks. Looks like your last set was a little too much on the conservative side?

I am going to try your measurements for a while and see how they look. Thanks again.

JIm
 
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