Fuel sight gauge question

Vance Atkinson


Sorry I didn't get to this sooner but just got back from a week La La land in Calif....and am now going thru the emails.

SO... Only #1 is acceptable  as Marc pointed out.  It is easy to remove the bubble and leave the background plate in place by taking a Dremel tool and grinding off the two BID strips around the bubble, inserting a sharp chisel between the bubble and back plate and giving it a sharp whack and the bubble will come off in one piece.

 Those two BID strips are the safety net that holds the bubble in place as a last ditch effort to stop leaks into the cabin area and secures the bubble in place so it cannot move....ever.

The bubble is made from P.E.T.G. plastic.  It is particularly slippery when it comes to bonding it to anything.... thus capturing it with the two BID is the purpose of the 2 BID.

  SO, drilling a hole in the bubble and sealing it will not assure that the hole sealing fix wont pop out at some later date and fill your fine machine with expensive fuel, yeah imagine coming out the the hangar and finding a swimming pool of fuel in the back seat area !

The problem of the fuel not flowing into the the bubble is most likely caused by a plugged lower outflow hole.  If the upper outflow hole is plugged then a small amount of fuel will enter the bubble chamber but not register the correct amount.

The plugged hole can most likely be epoxy wicked into it during assembly.  Less likely is debris  has clogged the hole.  After bubble the bubble is removed , you can redrill the hole using a vacuum cleaner to suck the small chips away.  You can drill the hole larger if you wish but the fuel will slosh around more in the gauge (less stable)  as you increase to a larger diameter .

I send out replacement bubbles in case your bubble winds up disfigured after removal.....most builders replace it anyway.  The biggest pain in the ass with this is you now have to re-zolatone the area around the gauge where you sanded off and replaced the 2 BID .  And that means a lot of masking off in the rear seat area (especially the canopy ) to stop the insidious zolatone over spray from spreading to unwanted areas......

As usual, the fix is pretty easy but the finish work will be several hours.

Vance Atkinson

On 7/11/2021 9:03 PM, Marc J. Zeitlin wrote:

Hi Marc.  On my pilots fuel site gauge Tyr fuel isn’t filling into the site gauge.

I assume you're referring to Vance Atkinson's sight gauges. I've copied him on my response.
The passenger site gauge fills fine. Any suggestions on how to correct this?  I remember the pilots side filling up 11 years ago last time i put gas in it.  I tried sloshing the fuel around. No luck.

Sounds like some crud clogged up the lower hole in the back plate. I can think of two possible solution, neither one wonderful:
  1. Remove the forward clear plate of the sight gage, drill out the backing plate hole, and reinstall the clear forward plate
  2. Carefully drill through the clear plate and through the backing plate with a plastic drill, and then seal up the clear plate hole with some fuel proof hole sealant
I don't particularly like #2, but it would be less work than #1.

Vance? Do you have any other methods I'm not aware of?

Marc J. Zeitlin                      marc_zeitlin@...
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