Shaw fuel cap difference?

[Jim Peace]

What is the difference between a shaw 431-9 and a 431-9R?  I have two -9Rs on my plane.

[Hank]

You mean other than the word "ROSS"? What "ROSS" means, I don't know.

@OSUAV8TER may know.

[Andy95W]

Jim- I have one of each.  They appear to be interchangeable.

This is the -9:

 

This is the -9R:

[OSUAV8TER]

The difference between the 431-9 and the 431-9R is the way they lock into the fuel cell adapter. When you put them lock them in, the plunger should be facing the tail of the airplane. 

[Jim Peace]

11 minutes ago, OSUAV8TER said:

The difference between the 431-9 and the 431-9R is the way they lock into the fuel cell adapter. When you put them lock them in, the plunger should be facing the tail of the airplane. 

okay thanks.....Mine are not original to the airplane.....Took what I could find at the time....mine are about 30-45 degrees off from facing aft....

[Andy95W]

1 hour ago, OSUAV8TER said:

The difference between the 431-9 and the 431-9R is the way they lock into the fuel cell adapter. When you put them lock them in, the plunger should be facing the tail of the airplane. 

Does that mean the “R” goes on the Right wing?  That’s where mine is.  I didn’t try to swap them. I’ll try that next. 

[OSUAV8TER]

44 minutes ago, Andy95W said:

Does that mean the “R” goes on the Right wing?  That’s where mine is.  I didn’t try to swap them. I’ll try that next. 

That is unclear to me why it is denoted R. It comes down to how it is oriented on the wing of the plane. The 431-9 and the 431-9R have different bottoms to the cap. I'll snap a photo today.

[Missile=Awesome]

On 10/1/2020 at 7:56 AM, Andy95W said:

Does that mean the “R” goes on the Right wing?  That’s where mine is.  I didn’t try to swap them. I’ll try that next. 

Might be on to something there Andy.  I am going to check ours.

[LantisPDX]

I am really curious what the difference between the 431-9 and 431-9R caps is if anyone has figured this out.

My plane has two 431-9 caps currently. The left wing seems correct with the tab straight back, but the right wing cap is 20-30 degree rotated clockwise from being inline. 

The theory that a 431-9R might stand for right wing but that could also be a coincidence. I'd be really interested to know more about this. Has anyone found a 431-9 and 431-9R on the same plane and aligned correctly?

Thanks!

Erik

[carusoam]

Great question for @OSUAV8TER (above)... what does the R stand for..?

I think I remember the question from before... so the answer may be around here somewhere...

Best regards,

-a-

[ArtVandelay]

Revised? How would you look up if there was a service bulletin on a fuel cap?

[LantisPDX]

I got too curious and I ordered a 431-9R. I should have it in a few days and I can get this figured out. In looking at photos it seems to be rotated 20 degrees when compared to the 431-9. It’s pretty hard to tell without a physical example. Fingers crossed that it’s what I am thinking.

[mooniac15u]

20 minutes ago, LantisPDX said:

I got too curious and I ordered a 431-9R. I should have it in a few days and I can get this figured out. In looking at photos it seems to be rotated 20 degrees when compared to the 431-9. It’s pretty hard to tell without a physical example. Fingers crossed that it’s what I am thinking.

Can't you just look at the adapter rings on each tank and see if the notches for the fuel caps are in the same positions?

[LantisPDX]

On 12/1/2020 at 1:19 PM, mooniac15u said:

Can't you just look at the adapter rings on each tank and see if the notches for the fuel caps are in the same positions?

The notches on my left and right tank are different as they align the fuel caps differently. Using the same cap the left is perfect and the right tab is angled towards the wing tip. 
That was what made me think it might be a 431-9/431-9R difference.

[LantisPDX]

I received the 431-9R cap today and was able to test fit it. I am uploading photos in case it helps someone else. The pinkish cap is the 9R.

The 9R cap fits the opening the same as the 9 caps. The biggest difference seems to be a bigger mechanical stop for counter rotation.
 

Somewhat comically the tab on the 9R for my plane is oriented inboard about as far as the 431-9 had pointed outboard.

[Guest]

There are a few Mooney service kits regarding fuel caps.  I’ve seen many airplanes with the fuel caps indexed incorrectly, there are also some with a restrictor plate added to the existing filler neck to keep Jet A fuel out.  These also got a new fuel cap.

Clarence 

[AIREMATT]

I think you can misalign them when replacing the small center o-ring. See the SB M20-229-A (downloads) and be sure the top and bottom are put together correctly. If I remember from replacing them with my A&P, they could be reassembled rotated, but wouldn’t line up fore/aft on top when closed. They tab would point left or right of aft.

Was too long ago to remember the details other than that