I believe there's a paper gasket that goes there.
I would never use RTV - what color is it , blue ?
I never ever use that stuff in engines.
I will use black really good stuff - the one I like I get from Toyota.
On clean surfaces without a gasket, it seals perfectly.
On a used paper gasket it seals perfectly.
There is no way to advance the situation without removing the offending
part, inspecting and cleaning, and carefully reassembling with good
workmanship and quality materials and parts. But you knew that.
Any attempts to add onto the outside of a leaky area are temporary or
emergency measures at best.  Nothing at all like disassembly and inspection
for starters.
It's super easy to make a paper gasket too.
I also just use Permaetx red High Tach in the brush-on can on both sides of
a paper gasket.
It's a really easy repair. And rewarding when the leak is gone.
Check that the flange is flat, they can get bent from repeated tightening.
File to flatness by hand if needed.

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Allan Streib
Sent: Sunday, December 02, 2007 5:10 PM
To: vanagon@GERRY.VANAGON.COM
Subject: leaking oil at filler tube

My motor is leaking oil (just a drop or two on the floor in the
garage) where the filler tube meets the case.  Looks like an attempt
was made to "seal" it with RTV, or perhaps the proper gasket was not
at hand when the current engine was installed (it's not the original).

Is this a common area of leakage (i.e. maybe there IS a gasket and it
leaks anyway, and the RTV was globbed on later as a "fix" ??

Allan