lml@lancaironline.net Mailing List Archive

Art

Actually-- It's a good hangar "floor" preflight check. There are two drains-usually on left side by the nose gear door (sniffle valve on the right).
One, ( the engine driven fuel pump) may drain oil or fuel-- depending which seal is leaking. Fuel is especially bad as it is a precurser to fuel leaking by the oil seal and filling the crankcase.

The other drain is the one in the previous post. The fuel manifold drain. Another bad (grounding) sign.

A blue stain on the belly or a spot on the hangar floor is a sign.

By the way-- a black (oil) spot on ground under sniffle valve on hangar floor is a indicator that intake valve guides are worn. If you pull an intake pipe, you'll find oil inside. Time to think about a top o'haul.

Charlie K.

----- Original Message ----
From: Art Bertolina <artbertolina@earthlink.net>
To: lml@lancaironline.net
Sent: Monday, May 14, 2007 10:26:56 PM
Subject: [LML] Re: Continental Engine fuel Sys.

Charlie

this sound like it would be a good annual inspection check

if it is not already.

Art

----- Original Message -----

From: Charlie Kohler

To: lml@lancaironline.net

Sent: Monday, May 14, 2007 6:29 AM

Subject: [LML] Continental Engine fuel Sys.

The thread regarding water/vent plugging issue has missed a potential cause of this problem. Having both Left/Right tank selections responding exactly alike would lead me to a common cause.  One is-- a slit/crack/porosity in the diaphragm in the fuel manifold valve on top of the engine.

If one exists --the engine driven pump will overcome it initially-- but then as leak (crack) enlarges-- it'll require electric pump lo-- then high to keep the engine running. This might be on one flight--or ten. But eventually the diaphragm will not contain the pressure to overcome the spring, closing the valve and the engine will quit.

To test--Put a bucket under sniffle valve-- Remove the drain line (rubber hose on bottom of manifold valve) and turn pump

on high mixture and throttle in. ANY fuel coming out drain is serious and the valve must be overhauled.

Engines stored for long periods are really susceptible to this problem.

Charlie K.