Uneven Fuel Flow

R

robins

New member
For all of you who have experienced uneven fuel flow (more from the left or the right tank), here something that worked for me:

Symptom:

More fuel burning from Right Tank than Left Tank.

Solution:
1: Replace the fuel cap rubber gaskets ($11/pair)
2: Lift the Left wing ever so slightly by shortening the lower rear Left Strut one-half turn. It's an adjustable bolt and can be easily done in 10 minutes. You will need a helper to lift the wing so that the bolt can more easily be removed and then replaced after shortening.

Thanks to:
Jerry Mehlaff Jr @ ACA
Ed Nelson @ Sidney Aviation

Jim Robins
N87VF/2007 7GCBC High Country
 
Jim-

While it may "solve" uneven fuel flow even 1/2 turn will have enough effect that a properly rigged aircraft will be ever so slightly out of rig.............slight but noticeable to a discerning pilot in smooth air.

I've never seen perfectly even fuel flow in any aircraft that fed from both tanks simultaneously due to slight differences in plumbing etc.

Tom-
 
Well, Jim's plane was a little out of rig. We actually were discussing his left wing heaviness, and the fuel burn came along for the ride. :)

I am happy that also worked out for you.

So, yeah, be careful with strut adjutment and rigging. Take baby steps (i.e. one change at a time) to make sure you can return the aircraft to where it was and also notice the effect of what you did.
 
Jerry-

Thanks for the additional info, makes more sense now.

I caution everyone to have the ball centered in smooth air when checking rigging, mine was ever so slightly out of rig that even in smooth air it frequently seemed OK.............I finally gave it a half turn of wash in and was amazed at the result.................it went from a slight nagging wing heaviness to perfect.

Tom-
 
I had a similar problem. One day I blew backward thru the vent tube. Fuel came out of the top of the tanks, I had removed the caps. And ever since then the fuel has burned somewhat even. Before the right tank would not feed, The left tank would be almost empty and the right tank would be full. After blowing back thru the vent that stopped. Maybe the flapper inthe right tank was stuck a little? Anyhow, it worked for me.
 
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