I recently bought a CH-750 in Oklahome and did all my local flying there, resulting in flight durations of two hours or less. Finally it was time for an "extended" cross-country from Cushing OK (CUH) to my home,Rockport TX (RKP). During the flight I found that I had essentially no fuel flow from the right-hand tank. The engine also quit a couple of times. I have reversed fuel tank caps to see if the problem reversed. With only half-full tanks it appeared the problem just went away. However, yesterday I flew for two hours after first topping off to the brim and got similar results as during the cross-country flight. I landed with 6.5 gal in the left tank and 9.5 in the right. In every instance as soon as I land the fuel immediately evens out. Incidentally, I also get a small amount of fuel seepage from the caps each flight. Now I am unwilling to go on extended flights.


I am hungry for suggestions/ideas.  HELP!

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Comment by Jim Nelson on August 24, 2011 at 8:34pm
I sent you a reply under your "door" problem.  It is my solution to this "some times problem" that I will not let myself get into with fuel flow not getting there all the time--
Comment by Peter Bennett on June 29, 2011 at 7:15am
Wayne, great news! There's also a guy in the Houstom area building a 750, so you two can share much info. I have never built anything in my life, so I am very dependent on people like you who can actually DO things. I will be happy to fly up to Sinton almost any time you like.  By the way, "performance" is a subjective area, depending on the prop, engine, fuel load, your (and your passenger's) weight, and your familiarity with the 750. Shoot me an email giving me the best day/time to show up. Peter
Comment by Wayne Maloy on June 28, 2011 at 9:32pm
Peter, We met a couple of weeks ago when you landed at T69, Sinton Tx. After looking your CH750 over I ordered the CH750 rudder kit and will soon start building. Was just curious about the performance. Stop by any time. Wayne
Comment by Peter Bennett on May 31, 2011 at 5:00pm
The left tank was empty (as I recall) and the right had something like nine gal remaining. I was worried that something might happen when I set up for landing, and indeed I had engine failure. Since I was involved in landing, I didn't have much time to play around. However, once on the ground the tanks equalized and the engine ran fine. I don't have a fuel pump, although I met a 701 owner who had added one, and at the time I wondered why.  In reading some of the responses I think others have experienced uneven fuel flow issues. If there is more involved I haven't stumbled on what else might be going on.
Comment by Ken Ryan on May 31, 2011 at 3:23pm
Was one tank completely dry when the engine stopped both times? How did you get the engine re-started? Do you have a fuel pump? Did you cycle the fuel pump or just crank the starter. It sounds like there's something other than just uneven fuel flow going on.
Comment by Peter Bennett on May 28, 2011 at 7:11am
Yesterday I flew straight & level in smooth air for a couple of hours with the new fuel caps from Zenith installed.. Initially the left tank dropped to 9 gal while the right tank remained at 12 gal.  But then they equaled out. So, it seems possible that my fuel flow issue could be resolved.  For now I'm going to assume it is.  The best part of this issue has been the response from all you "Z" owners. We are not alone.
Comment by Brian Fitzpatrick on May 27, 2011 at 9:25pm

comment by Brian Fitzpatrick, May 27/11 at 7:15 PM PDST


Re: fuel flow issues 750

I am building a 750 and like you, believe reliable fuel flow is always a good thing.  Found all the comments by you and others interesting and helpful for my build . As a result, I think I will be using larger fuel lines, low restriction filters, moron simple fuel routing with as few connectors as possible and old style ram air-pressure fuel caps. I wonder if a header tank collecting fuel from the tanks would help equalize things and or perhaps check valves to off-set left turn or wing low syndrome?   Good luck.   Brian

Comment by Peter Bennett on May 25, 2011 at 4:46pm
I just installed the new fuel caps received from Zenith and flew about 30 minutes, took a helf-hour break and flew another 70 minutes. No problems.  However, the true test will be when I can fly straight & level for two or three hours, which will be soon. I am looking forward to moving on from this issue to the fun stuff, like LANDING TECHNIQUE & PERFORMANCE.
Comment by FRed Sanford on May 23, 2011 at 7:36pm


The fuel lines with no valves are a problem. 5 years ago I had this happening , and did some tests with tanks and lines etc. and the slightest bubble would interfere with the flow. One would usually drain before the other started. Used a tv inside the gas tank and discovered that the finger screens actually had bubbles inside. Don't ask me why.

I put a valve in each line on the floor under my left leg. I keep them both open until they get unbalanced, then practice fuel control. .....No problems since......Fred

Comment by Jim Derickson on May 23, 2011 at 7:16pm
Also I tailed the aircraft down , to simulate a steep departure and then took the fuel line off at the carb and had a gravity flow of 15 gallons an hour  with 3/8 lines, FYI

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