Tom,
As with most everything J3 related, Univair does have new gas cap/float/wire available. The float is now the same black plastic/foam stuff used in car gas gauge sending units.
They come fully assembled and this leads me to a question. With the original gauge, Pipers intent was that when the bend in the wire rested on the tube coming out of the cap, you were supposed to have 30 minutes of fuel. With the A-65 that was a little over 2 gallons.
I flew a friends J3 recently that has a new Univair gas cap. Had a great time and landed with the bend in the wire just resting on the tube. Filled up the tank and was shocked to find that I had barely over 1 gallon left in the tank! I've talked with him about this and we plan to drain his tank, then put 2.5 gallons in and either mark or re-bend his wire.
You can easily make a new cork and indicator. A length of welding rod (get something that won't rust) and some cork from the craft store (I have also seen people purchase a sending unit from NAPA with the approx size float to use). You may have to use two or three pieces of cork stacked to get the right dimenion. a washer soldered above and below the cork will keep it in place. coat the cork with several coats of fuel proof epoxy to keep it from getting saturated.
As you cut the wire to length and bend it, I'd suggest leveling the fuselage and putting 30 minutes worth of fuel in your tank. (~2.25 gal for 65hp, 3 gal for 90hp). Install the wire through the cap and install the cap. Trim the wire so it is about 1 inch above the tube, then mark the wire at the tube (this removes the extra weight of the wire, giving a more accurate reading). Bend the wire 90* at the mark and trim if necessary. Now you have "calibrated" your gas gauge!
Good luck!
John Scott
