---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Sun 04/22/12: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:10 AM - Re: N912RV power failure on takeoff (Thom Riddle) 2. 07:54 AM - Re: Fuel filters (FLYaDIVE) 3. 08:08 AM - Re: Re: N912RV power failure on takeoff (FLYaDIVE) ________________________________ Message 1 _____________________________________ Time: 05:10:12 AM PST US Subject: RotaxEngines-List: Re: N912RV power failure on takeoff From: "Thom Riddle" Bob, "After we removed the electric pump it was no longer restricted. The removal process cleared the obstruction. " I suspect the reason that removing the fuel pump removed the "obstruction" is that diaphragm pumps all have check-valves. They won't work without one-way check-valves. I'd bet that if you had tried blowing air through the system from the tank towards the engine (with tube disconnected at engine), you would have been able to. -------- Thom Riddle Buffalo, NY (9G0) Kolb Slingshot SS-021 Jabiru 2200A #1574 Tennessee Prop 64x32 Truth is what stands the test of experience. - Albert Einstein Read this topic online here: http://forums.matronics.com/viewtopic.php?p=371468#371468 ________________________________ Message 2 _____________________________________ Time: 07:54:43 AM PST US Subject: Re: RotaxEngines-List: Fuel filters From: FLYaDIVE Where are you guys getting your fuel filters from? If they are automotive, read the packaging, does it state acceptable for ethanol? If they are aviation, does it state acceptable for ethanol? If they are automotive CAN one ASSume the manufacture has run test to make sure they are acceptable for MoGas? If you do not have PROOF then run your own test for a couple of MONTHS - By having the fuel filter filled and sitting in MoGas AND by exchanging (flowing) (replacing) the gas every week. FLOW RATE - I know you guys are EXPERIMENTAL - But did you know there is an FAA requirement AC43.13 that states that in a gravity system the free flow rate of a system should be 8 times the fuel requirement of an engine at cruse. So, lets say you burn 2.5 GPH the free flow rate should be: 2.5 x 8 = 20 GPH. That means the DIAMETER of your fuel lines, the SIZE of your FUEL FILTER and the restrictions of your fittings should allow 20 GPH. That is NOT MUCH. Does your system comply? Can you say Fuel Starvation, can you say Vapor Lock? I am very much in favor of CLEAR 'plastic' fuel filters. And I would, if your fuel system takes the fuel flow through the cabin - I would like to see them placed where you can SEE them during flight if at all possible. Metal fuel filters work just fine. But, Roger, 100 hours or not, how are you going to inspect them? You can't - You sure can replace them. You can back flush them - - BUT! You still do not know how clean you got them, even after back flushing them. IF you want to reuse a filter (Metal or Plastic) you could always set up an apparatus and TIME the flow rate for a NEW filter and re-time it after back flushing it. That way you will have real data to verify a safe fuel system. Otherwise replace filter or play Russian Roulette. Barry On Sun, Apr 22, 2012 at 12:35 AM, Roger Lee wrote: > > The issue with some filters is that the ethanol will make them swell and > reduce flow. Make sure you use a good quality filter meant to handle any > fuel you may use. Some filter elements will break down after long exposure > to ethanol. Ethanol will cause many plastic filters to become soft. It is > advisable to use a metal filter with a metal mesh screen. Then there is > never a worry. There is no need to have a clear filter so you can see > through it because you should be checking the filter every 100 hours or > each annual. > > -------- > Roger Lee > Tucson, Az. > Light Sport Repairman - Maintenance Rated > Rotax Repair Center - Heavy Maint. Rated > Home 520-574-1080 TRY HOME FIRST > Cell 520-349-7056 > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=371460#371460 > > ________________________________ Message 3 _____________________________________ Time: 08:08:20 AM PST US Subject: Re: RotaxEngines-List: Re: N912RV power failure on takeoff From: FLYaDIVE Good point Thom: I suspect the reason that removing the fuel pump removed the "obstruction" > is that diaphragm pumps all have check-valves. They won't work without > one-way check-valves. I'd bet that if you had tried blowing air through the > system from the tank towards the engine (with tube disconnected at engine), > you would have been able to. > > -------- > Thom Riddle > Buffalo, NY (9G0) > Kolb Slingshot SS-021 > Jabiru 2200A #1574 > Tennessee Prop 64x32 > > Truth is what stands the test of experience. > - Albert Einstein > Experience is what you get from failures. - Barry The diagnosis process was faulty. You MUST start from a known. The known being there was no fuel flow. Then check as much of the system as possible with disturbing as little as possible. One thought that came to mind was Mud Daubers - I say that because there were no mentions of assembly procedures. Barry ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.