---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Thu 09/13/07: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:17 PM - 912ULS and XCOM760 Problem (Tommy Walker) 2. 03:07 PM - Installing new Rings in a 914 (Paul McAllister) 3. 04:37 PM - Re: 912ULS and XCOM760 Problem (Roger Lee) 4. 04:40 PM - Re: Installing new Rings in a 914 (Roger Lee) 5. 05:38 PM - Rotax 912UL fuel flow sensor installation (Paul Kuntz) 6. 06:38 PM - Re: Rotax 912UL fuel flow sensor installation (george may) 7. 08:06 PM - Re: 912ULS and XCOM760 Problem (James Shumaker) 8. 08:36 PM - Re: Rotax 912UL fuel flow sensor installation (Paul Kuntz) 9. 09:59 PM - Re: Rotax 912UL fuel flow sensor installation (paul wilson) ________________________________ Message 1 _____________________________________ Time: 02:17:48 PM PST US Subject: RotaxEngines-List: 912ULS and XCOM760 Problem From: "Tommy Walker" Rotaxers, I have a problem some of you may have experienced and thought I might get some help. I've already talked with a couple of the people on this list. This will be a little long, but if you got the time to read it, you might be able to help me out..... Here goes: (copy of email sent to XCOM support).... I bought an XCOM760 from you a couple of years ago (Invoice # 807), and I am just now getting to the point of using it. I have a problem and hope that you can point me in the right direction. The Xcom is mounted in a Zenith 701 with Rotax 912ULS. I have the 22000 uF capacitor installed and it appears to be working correctly. At engine idle, there is a slight noise entering the system when I press the PTT. When I increase RPM, the noise level increases proportionately. At RPM levels over 4000, the output seems to be so overcome by a high pitch whine that the message is unreadable. There is no outside noise when the PTT is not depressed. The radio receiver function works properly on all channels, just problems when mike button is pressed at higher RPM. Heres what Ive done: Installed a line filter just ahead of the XCOM. Isolated the headphone jacks so that they do not contact ground. Moved the 22000 uF capacitor to just in front of the XCOM in the electrical circuit. Tested the radio after having removed the fuses of all components except the tach. Substituted an antenna from a handheld transceiver for the Commant antenna. Removed the Commant antenna from the airplane and laid it on a plastic cover to see if it was introducing a ground loop. The noise was still present. Made up new antenna cable with suggested length of 7.9 ft. Hooked the XCOM to another battery, cranked up the 912 and again tried to communicate. None of the above reduced the noise level when the radio is used to communicate. If you have any suggestions, please let me know. Tommy Walker (End of Email) Thanks for any suggestions from the list. -------- Tommy Walker Read this topic online here: http://forums.matronics.com/viewtopic.php?p=134266#134266 ________________________________ Message 2 _____________________________________ Time: 03:07:52 PM PST US From: Paul McAllister Subject: RotaxEngines-List: Installing new Rings in a 914 Hi all, I purchased a 914 a year ago that had been run in a test cell for 100 hours and then it sat for a couple of years. I pulled the heads to inspect for corrosion and found small amount on the valve seats so I had them re seated, however I decided since I have it in bits to put a new set of rings in it. So, after such a long winded introduction I would like to know if it is required to hone the bores so that the new rings will seat, or would I risk damaging the coating on the cylinder bores ? Thanks, Paul --------------------------------- Catch up on fall's hot new shows on Yahoo! TV. Watch previews, get listings, and more! ________________________________ Message 3 _____________________________________ Time: 04:37:44 PM PST US Subject: RotaxEngines-List: Re: 912ULS and XCOM760 Problem From: "Roger Lee" Hi Tommy, WOW, a really tough one. I'm not sure what to say. Just thinking out loud here. Is the capacitor placed in line correctly? Could it just be hooked up to a different terminal? Doesn't sound like it is filtering much at all. Is there more than one way to hook it up? Maybe wire the radio up differently? Have you ask a radio tech on your field or in the area? I'm at a loss. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=134282#134282 ________________________________ Message 4 _____________________________________ Time: 04:40:28 PM PST US Subject: RotaxEngines-List: Re: Installing new Rings in a 914 From: "Roger Lee" You can download the heavy maint. manual from the Rotax website for the 914 and it will tell you for sure. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=134284#134284 ________________________________ Message 5 _____________________________________ Time: 05:38:14 PM PST US From: "Paul Kuntz" Subject: RotaxEngines-List: Rotax 912UL fuel flow sensor installation I'm looking for advice and technical information on installation of a fuel flow sensor on the 912UL engine in my Pipistril Sinus motorglider. Pipistrel offers two potential locations -- one is in the main fuel feed between the gascolator and the fuel pump; the other is in a fuel line leading from the fuel splitter on one of the carburetors. The Pipistrel support staff notes that if the sensor is placed between the gascolator and the fuel pump, it will be inaccurate by the amount of fuel is being returned to the tank in the fuel return line leading out of the splitter. In that case, the fuel flow instrument will have to be "adjusted" by some undefined amount to account for the fuel return. The alternative, however, will measure the fuel flow to only one of the carburetors, so I assume the instrument will have to be adjusted to double the reading in that case. This assumes that such an adjustment is possible, and it also assumes that the fuel flow to the two carburetors is identical (although if the carburetors are balanced, that is not an unreasonable assumption). What are the rest of you doing? Also, the fuel flow sensor that came with my kit is a Brauniger device. I plan to use a Dynon FlightDek D180. Does anyone know the electrical output characteristerics of the Brauniger flow sensor, and can you confirm (or deny) that it is compatible with the Dynon? Do you know whether the Dynon allows the sort of calibration adjustments necessary to address the installation questions above? Thanks a lot, Paul Kuntz http://www.pipistrelbuilders.com ________________________________ Message 6 _____________________________________ Time: 06:38:43 PM PST US From: george may Subject: RE: RotaxEngines-List: Rotax 912UL fuel flow sensor installation Paul-- I have the Dynon 180 and am using their fuel flow meter. I have it in li ne with the pump and just before the return line on a 912uls. I initially measured the fuel return to determine what correction would be necessay to apply. My return line has a restrictor in it so the return flow is pretty s mall. If I remember correctly, the return flow was in the vicinity of about 13-15 onces per hour. This is a pretty small value considering that you wi ll be burning about 5 gallons per hour. I have a 24 gallon capacity, about 4 hours cruise, the returned fuel is a very minor issue. After 150hours on the plane, I basically just disregard the return flow. So, a long winded way of saying go with the placement of the fuel flow i n line with the gascolator and pump. Good luck George May 601XL 912s 150 hours ngines-list@matronics.comSubject: RotaxEngines-List: Rotax 912UL fuel flow sensor installation I'm looking for advice and technical information on installation of a fuel flow sensor on the 912UL engine in my Pipistril Sinus motorglider. Pipistr el offers two potential locations -- one is in the main fuel feed between t he gascolator and the fuel pump; the other is in a fuel line leading from t he fuel splitter on one of the carburetors. The Pipistrel support staff notes that if the sensor is placed between the gascolator and the fuel pump, it will be inaccurate by the amount of fuel i s being returned to the tank in the fuel return line leading out of the spl itter. In that case, the fuel flow instrument will have to be "adjusted" b y some undefined amount to account for the fuel return. The alternative, however, will measure the fuel flow to only one of the car buretors, so I assume the instrument will have to be adjusted to double the reading in that case. This assumes that such an adjustment is possible, a nd it also assumes that the fuel flow to the two carburetors is identical ( although if the carburetors are balanced, that is not an unreasonable assum ption). What are the rest of you doing? Also, the fuel flow sensor that came with my kit is a Brauniger device. I plan to use a Dynon FlightDek D180. Does anyone know the electrical output characteristerics of the Brauniger flow sensor, and can you confirm (or de ny) that it is compatible with the Dynon? Do you know whether the Dynon al lows the sort of calibration adjustments necessary to address the installat ion questions above? Thanks a lot, Paul Kuntz http://www.pipistrelbuilders.com _________________________________________________________________ Capture your memories in an online journal! http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=us ________________________________ Message 7 _____________________________________ Time: 08:06:14 PM PST US From: James Shumaker Subject: Re: RotaxEngines-List: 912ULS and XCOM760 Problem Tommy=0A=0AOne of the kitfox pilots reported similar symptoms and his solut ion was to run a dedicated ground from the voltage regulator frame to a gro und point on the frame. =0A=0AJim Shumaker=0A=0A=0A----- Original Message ----=0AFrom: Tommy Walker =0ATo: rotaxengines-list@ma tronics.com=0ASent: Thursday, September 13, 2007 2:15:18 PM=0ASubject: Rota xEngines-List: 912ULS and XCOM760 Problem=0A=0A=0A--> RotaxEngines-List mes sage posted by: "Tommy Walker" =0A=0ARotaxers,=0A=0AI have a problem some of you may have experienced and thought I might get so me help. I've already talked with a couple of the people on this list.=0A =0AThis will be a little long, but if you got the time to read it, you migh t be able to help me out.....=0A=0AHere goes:=0A=0A(copy of email sent to X COM support)....=0A=0AI bought an XCOM760 from you a couple of years ago (I nvoice # 807), and I am just now getting to the point of using it. I have a problem and hope that you can point me in the right direction.=0A=0AThe Xcom is mounted in a Zenith 701 with Rotax 912ULS. I have the 22000 uF cap acitor installed and it appears to be working correctly. =0A=0AAt engine id le, there is a slight noise entering the system when I press the PTT. When I increase RPM, the noise level increases proportionately. At RPM levels over 4000, the output seems to be so overcome by a high pitch whine that t he message is unreadable. There is no outside noise when the PTT is not de pressed. The radio receiver function works properly on all channels, just problems when mike button is pressed at higher RPM.=0A=0AHere=99s wha t I=99ve done:=0A=0AInstalled a line filter just ahead of the XCOM. =0A=0AIsolated the headphone jacks so that they do not contact ground. =0A =0AMoved the 22000 uF capacitor to just in front of the XCOM in the electri cal circuit.=0A=0ATested the radio after having removed the fuses of all co mponents except the tach.=0A=0ASubstituted an antenna from a handheld trans ceiver for the Commant antenna. =0A=0ARemoved the Commant antenna from the airplane and laid it on a plastic cover to see if it was introducing a gr ound loop. The noise was still present.=0A=0AMade up new antenna cable wit h suggested length of 7.9 ft.=0A=0AHooked the XCOM to another battery, cran ked up the 912 and again tried to communicate. =0A=0ANone of the above red uced the noise level when the radio is used to communicate. =0A=0AIf you h ave any suggestions, please let me know.=0A=0A=0ATommy Walker=0A(End of Ema il)=0A=0AThanks for any suggestions from the list.=0A=0A--------=0ATommy Wa lker=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp://forums.matronic ======================= ________________________________ Message 8 _____________________________________ Time: 08:36:01 PM PST US From: "Paul Kuntz" Subject: Re: RotaxEngines-List: Rotax 912UL fuel flow sensor installation Thanks, George. That sounds reasonable. I assume that the Dynon does have some means of calibrating the fuel flow readings -- true? Regards, Paul Kuntz ----- Original Message ----- From: george may To: rotaxengines-list@matronics.com Sent: Thursday, September 13, 2007 6:37 PM Subject: RE: RotaxEngines-List: Rotax 912UL fuel flow sensor installation Paul-- I have the Dynon 180 and am using their fuel flow meter. I have it in line with the pump and just before the return line on a 912uls. I initially measured the fuel return to determine what correction would be necessay to apply. My return line has a restrictor in it so the return flow is pretty small. If I remember correctly, the return flow was in the vicinity of about 13-15 onces per hour. This is a pretty small value considering that you will be burning about 5 gallons per hour. I have a 24 gallon capacity, about 4 hours cruise, the returned fuel is a very minor issue. After 150hours on the plane, I basically just disregard the return flow. So, a long winded way of saying go with the placement of the fuel flow in line with the gascolator and pump. Good luck George May 601XL 912s 150 hours ------------------------------------------------------------------------- --- Date: Thu, 13 Sep 2007 17:37:37 -0700 From: paul.r.kuntz@gmail.com To: rotaxengines-list@matronics.com Subject: RotaxEngines-List: Rotax 912UL fuel flow sensor installation I'm looking for advice and technical information on installation of a fuel flow sensor on the 912UL engine in my Pipistril Sinus motorglider. Pipistrel offers two potential locations -- one is in the main fuel feed between the gascolator and the fuel pump; the other is in a fuel line leading from the fuel splitter on one of the carburetors. The Pipistrel support staff notes that if the sensor is placed between the gascolator and the fuel pump, it will be inaccurate by the amount of fuel is being returned to the tank in the fuel return line leading out of the splitter. In that case, the fuel flow instrument will have to be "adjusted" by some undefined amount to account for the fuel return. The alternative, however, will measure the fuel flow to only one of the carburetors, so I assume the instrument will have to be adjusted to double the reading in that case. This assumes that such an adjustment is possible, and it also assumes that the fuel flow to the two carburetors is identical (although if the carburetors are balanced, that is not an unreasonable assumption). What are the rest of you doing? Also, the fuel flow sensor that came with my kit is a Brauniger device. I plan to use a Dynon FlightDek D180. Does anyone know the electrical output characteristerics of the Brauniger flow sensor, and can you confirm (or deny) that it is compatible with the Dynon? Do you know whether the Dynon allows the sort of calibration adjustments necessary to address the installation questions above? Thanks a lot, Paul Kuntz http://www.pipistrelbuilders.com ist" target=_blank>http://www.matronics.com/Navigator?RotaxEngines-List p://forums.matronics.com ------------------------------------------------------------------------- ----- Make your little one a shining star! Shine on! ________________________________ Message 9 _____________________________________ Time: 09:59:32 PM PST US From: paul wilson Subject: RE: RotaxEngines-List: Rotax 912UL fuel flow sensor installation Matronics the host for this list sells a gadget that allows 2 sensors and subtracts them for precise flow measurements. PW ============== At 07:37 PM 9/13/2007, you wrote: >Paul-- > I have the Dynon 180 and am using their fuel flow meter. I have > it in line with the pump and just before the return line on a > 912uls. I initially measured the fuel return to determine what > correction would be necessay to apply. My return line has a > restrictor in it so the return flow is pretty small. If I remember > correctly, the return flow was in the vicinity of about 13-15 onces > per hour. This is a pretty small value considering that you will be > burning about 5 gallons per hour. I have a 24 gallon capacity, > about 4 hours cruise, the returned fuel is a very minor > issue. After 150hours on the plane, I basically just disregard the > return flow. > So, a long winded way of saying go with the placement of the > fuel flow in line with the gascolator and pump. > >Good luck >George May >601XL 912s 150 hours > > >---------- >Date: Thu, 13 Sep 2007 17:37:37 -0700 >From: paul.r.kuntz@gmail.com >To: rotaxengines-list@matronics.com >Subject: RotaxEngines-List: Rotax 912UL fuel flow sensor installation > >I'm looking for advice and technical information on installation of >a fuel flow sensor on the 912UL engine in my Pipistril Sinus >motorglider. Pipistrel offers two potential locations -- one is in >the main fuel feed between the gascolator and the fuel pump; the >other is in a fuel line leading from the fuel splitter on one of the >carburetors. > >The Pipistrel support staff notes that if the sensor is placed >between the gascolator and the fuel pump, it will be inaccurate by >the amount of fuel is being returned to the tank in the fuel return >line leading out of the splitter. In that case, the fuel flow >instrument will have to be "adjusted" by some undefined amount to >account for the fuel return. > >The alternative, however, will measure the fuel flow to only one of >the carburetors, so I assume the instrument will have to be adjusted >to double the reading in that case. This assumes that such an >adjustment is possible, and it also assumes that the fuel flow to >the two carburetors is identical (although if the carburetors are >balanced, that is not an unreasonable assumption). > >What are the rest of you doing? > >Also, the fuel flow sensor that came with my kit is a Brauniger >device. I plan to use a Dynon FlightDek D180. Does anyone know the >electrical output characteristerics of the Brauniger flow sensor, >and can you confirm (or deny) that it is compatible with the >Dynon? Do you know whether the Dynon allows the sort of calibration >adjustments necessary to address the installation questions above? > >Thanks a lot, >Paul Kuntz >http://www.pipistrelbuilders.com > > >ist" target=_blank>http://www.matronics.com/Navigator?RotaxEngines-List > >p://forums.matronics.com > > >---------- >Make your little one a shining star! >Shine on! ------------------------------------------------------------------------------------- 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.