Fuel Selector Oddity

[tonycondon]

I probably would've never gone down this rabbit hole except that I saw where Tim was selling replacement fuel selector placards and thought it was a good way to make my plane look nicer. As received I just have a bunch of label maker decals.

But then I got looking closer and realized that the positions of my fuel selector are WRONG!

My selector is Right - OFF, Aft-Left Tank, Left-Right Tank!

The handle is old imperial with three flats and one round. The stem on the selector matches i.e. there is only one orientation that is possible to mount the handle.

I think that the fuel channels are aligned like the middle row In The "shortcut to avoid" diagram in Neal Wrights article on fuel selectors. However the handle is flipped 180deg from that diagram.

Is it possible to flip the orientation of the stem wrt the brass spool? It looks like there is a pin that holds the stem to the spool so that could explain the 180 there.

What keeps the valve from rotating all the way around? In the photos I see in the fuel selector maintenance thread it is not obvious to me what stops the rotation.

[8342]

My guess is that when the selector was replaced they had to cut the stem down.
When they did so they did not orient the handle correctly and relabeled the positions to fix that mistake.

From the pictures there has been a fuel leak at some point. If it is with the valve that is currently installed you may want to replace the inner workings to fix it. If you do that you can orient the selector at that time.

Rick

[6643]

There is nothing inside the valve to keep it from rotating the full 360 degrees. There is a bracket (missing) that serves that purpose (17-51 in the parts manual).

Looks like the handle is off by 90 degrees clockwise. (As installed, forward should also be off.)

[tonycondon]

Interesting, that is what I expected from what I've been able to see of the inner workings of the valve, but I definitely encounter resistance if I try to turn my valve forward. I'm working on getting ahold of a parts selector to have a look at it and determine what needs to be done and then I'll decide how bad I want mine to match the beautiful placard thats on its way

[6597]

viewtopic.php?f=7&t=1227&p=8306&hilit=selector#p8306

Here's some previously posted pics of fuel selectors for Left(Left tank 9 O'clock)-Right(forward for right tank 12 O'clock)-Off(right 3 O'clock). Simple devices, the truncated cone that fits into the brass body has 2 holes drilled 90 degrees to each other. With all the fuel drained it's a matter of unscrewing the top bonnet and seeing how the holes are arranged to the body and adjusting the handle accordingly. Can't say I've seen an arrangement like yours, I'm guessing you have an earlier fuel system arrangement that does not have the crossover feed between tanks?

[6643]

If it's not working the way it should you might want to figure out why, to avoid a potential (in flight) problem down the line.

The fact that your valve does not operate the way it should tells me it has been "modified" and, as such, may not be airworthy. My guess is the valve is not the original, and has been "modified" to accept the original handle. Why it won't turn 360 degrees is a mystery, too.

You can probably pick up the stop plate from one of the aircraft junk yards, or make one if necessary.

[tonycondon]

viewtopic.php?f=7&t=1227&p=8306&hilit=selector#p8306

Here's some previously posted pics of fuel selectors for Left(Left tank 9 O'clock)-Right(forward for right tank 12 O'clock)-Off(right 3 O'clock). Simple devices, the truncated cone that fits into the brass body has 2 holes drilled 90 degrees to each other. With all the fuel drained it's a matter of unscrewing the top bonnet and seeing how the holes are arranged to the body and adjusting the handle accordingly. Can't say I've seen an arrangement like yours, I'm guessing you have an earlier fuel system arrangement that does not have the crossover feed between tanks?

Yep, I've looked over those great photos and Neal Wrights article. My logbooks indicate the fuel selector was replaced in 1976. No note of what type of selector etc. Correct that there is no crossover between tanks, its L-R-OFF. It did cross my mind that I could investigate without having to remove the entire selector by draining the fuel and removing the cap.