Leaking carburettor 912

Hi Ian

Before you commit to putting in a new seat there is one last try you can do at repair.  

1  Take the body with the seat and support it firmly on the bench with the seat exposed.  

2  Get a NEW punch with 60 degree cone on the end.  (do not use one that has been ground down) 

3  Place the punch on the seat (where the needle would contact the bore) 

4  Give it a light blow with a hammer

5  cross your fingers and reassemble....should work.

I have done this on many old carbs were the seat is somehow damaged or just picked up too much debris on the sealing area.  If that does not work then consider replacement of the seat.  Rotax has no seat replacement parts themselves and no guidance on how to do it, so be sure your working on an experimental and not certified engine.  

Cheers

Dear Rotax Wizard,

Thanks for that suggestion and I like your thinking and guess I have nothing to lose.

Cheers Ian

Yes, that's a chance, too.

But I had too many rounds of trying to get it sealed, searching for the reason, fuel in the fuselage (Taildragger, dripping fuel from air filter touched firewall, got to the inside, lake of fuel in the fuselage...) 

I just wanted to get it done and the valve seat did it so I would never start looking for other options again ;-)

So in the end I sent my carb to a recommended Rotax guy Wal here in Oz. I was reluctant to "tap" it. While I did try a little valve guide paste I probably did not persist enough or maybe it was too out of shape. Attached are some pictures taken thru a microscope of the old seat and the new seat.

Thanks for suggestions.

Regards Ian