Fuel Venting Problem

I am working hard to get the plane in shape to attend the Open Hangar Day at Zenith on the 21st, but am having a problem venting the fuel tanks.  With the fuel caps provided by Zenith, the left tank flows much faster than the right.  At Zenith's suggestion, I drilled a hole in the filler neck on the right side, but nothing changed.

I then borrowed a cap from a friend's Vagabond and put it on the right tank.  I had some success, so I bought 2 caps from Wag Aero, that have a copper tube coming out of the top of the cap and pointing forward, roughly 90 degrees.  This mirrored the one from the Vagabond.  Unfortunately, I still have the same problem, the right won't flow as fast, to the tune of about a 3 gal. difference showing up pretty quickly?

Next, I put the Vagabond cap back on the right and kept the new vented one on the pilot side.  We can see fuel vapor coming from that cap on the pilot side, but the problem still exists?  Any ideas out there?

And, we did extensive fuel flow testing of all the hoses and had no issues.  We had good flow on both tanks.  The problem seems to be in the venting.

Views: 2526

Replies are closed for this discussion.

Replies to This Discussion

Permalink Reply by david shrader on September 4, 2013 at 7:41pm
Permalink Reply by Doug MacDonald on September 6, 2013 at 8:55am

I'm not sure if this is any help but I experience the same sort of unequal fuel flow issue with my CH-701; the left tank drains faster than the right tank.  I have found the imbalance occurs until about the halfway point in the tanks and then the level generally equalizes.  Additionally, I have ground verified that with one tank empty, the other tank continues to flow fuel normally.  Of course, since this is a Canadian plane I have 3/8" aluminum fuel lines and AN fittings throughout most of my fuel system so I may have a more stable fuel flow than the stock rubber lines.  The WAG fuel caps do look interesting though and I have been thinking of trying them.

Doug M

CH-701 from scratch

NW Ontario, Canada

RSS

New from Zenith:

Zenith Planes For Sale 
  

Classified listing for buying or selling your Zenith building or flying related stuff...

Custom Instrument Panels
for your Zenith:

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, Dynon and Garmin avionics, and more.

Zenith Homecoming Tee:

Zenair Floats

Flying On Your Own Wings:
 A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

Aircraft Insurance:

 
 

West Coast USA:

 
Pro Builder Assistance:

 

Transition training:

Lavion Aero

K&S Aviation Services

Aircraft Spruce & Specialty for all your building and pilot supplies!

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

© 2024   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service