---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Thu 07/08/10: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:56 AM - Re: Re: rough running at 3400 RPM and above (Duncan & Ami McFadyean) 2. 04:13 AM - Re: Re: rough running at 3400 RPM and above (Robert C Harrison) 3. 05:38 AM - Re: 912ULS Recommended Oil (dashwood) 4. 05:59 AM - CHT temps (Thilo Kind) 5. 06:12 AM - Re: CHT temps (Roger Lee) 6. 06:15 AM - Re: 912ULS Recommended Oil (Roger Lee) 7. 08:51 AM - Re: rough running at 3400 RPM and above (MacDonald Doug) 8. 10:45 AM - Re: Re: 912ULS Recommended Oil (FLYaDIVE) 9. 02:38 PM - 582 oil (Michael Woolson) 10. 02:45 PM - Re: 582 oil (Blumax008@aol.com) 11. 03:00 PM - Re: 582 oil (FLYaDIVE) 12. 03:56 PM - Re: 912ULS Recommended Oil (rampil) 13. 05:36 PM - Re: 912ULS Recommended Oil (Roger Lee) 14. 07:52 PM - Re: Re: 912ULS Recommended Oil (dave) ________________________________ Message 1 _____________________________________ Time: 12:56:04 AM PST US From: "Duncan & Ami McFadyean" Subject: Re: RotaxEngines-List: Re: rough running at 3400 RPM and above There is also a filter in the mechanical fuel pump. Obviously there is no way of cleaning this. Only a fuel pressure test (measured downstream of the pump) will give a clue as to whether its blocked. Duncan McF. ----- Original Message ----- From: aoldman@xtra.co.nz To: rotaxengines-list@matronics.com Sent: Wednesday, July 07, 2010 9:55 AM Subject: Re: RotaxEngines-List: Re: rough running at 3400 RPM and above When you stopped the engine to check the plugs did you also check the fuel in the carb bowls. The fuel pump { or filter }may not be delivering sufficent fuel to keep it running at high RPM settings. Have you check the exhaust has not become obstructed while the engine was not being used , that problem can also become apparent at high RPM . Just some more things to check. Downunder MK111c ----- Original Message ----- From: Richard Girard To: rotaxengines-list@matronics.com Sent: Wednesday, July 07, 2010 3:02 PM Subject: Re: RotaxEngines-List: Re: rough running at 3400 RPM and above Have you checked all the pieces of the equalizer line between the two intake manifolds? Try checking the vacuum readings at the equalizer and then at the carb taps with the equalizer line connected to see if there's any gross difference. As long as you had the carbs off, did you pull the carb sockets and check them? I know you said they are recently replaced, but they're easy to check and it eliminates one more possible source of a leak. There was a bad batch a few years back that rotted out within a year. I couldn't see the cracks in mine until I got them off and used a strong light, then the cracks were obvious. What about the o-rings at the socket and those on the intake manifolds? Have you checked the diaphragms in the carb domes? You've had them out to raise the needle did you make sure the tab on the diaphragm is set in the slot in the carburetor body? Also, from the IPC, there are no o-ring seals on the throttle shafts? Have you miked them to see if the carb body is corroded or rotted out the throttle shaft bore? Personally, I wouldn't start messing with jetting until you've exhausted every possibility of a gross air leak. Rick Girard On Tue, Jul 6, 2010 at 8:57 PM, MacDonald Doug wrote: The saga continues... Tonight I pulled the carbs right off of the plane. I pulled them apart and this time got the float needles right out. There was a small chunk of silicone beside the needle in one of the carbs but after removing it and running the engine, there was little improvment if any. I was able to get it up to 4200 with the enrichener on but only the same old 3400 with the enrichener off. Other things I have tried is raising the needle one notch to full rich. This also made little to no difference. I stopped the engine while it was misfiring at 3400 RPM and pulled a couple of plugs. They were sooty white so I think we can say that this issue is definately a lean misfire. I read someplace in the parts manual that there are slightly larger main jets available when you run an air box. Since I have the original cone filters, I removed the airbox and ran it with them (also on the richest needle setting) and again the engine stumbles at about 3400 RPM. One thought I had tonight after all of this playing around is; is it possible that the throttle shaft o-rings could leak enough to cause this issue? I don't know that they are leaking but given that the carbs are over ten years old, it is possible. While I had the carbs apart I re-checked all of the other passages and found no buildup in any of them. Getting frustrating but this wouldn't be any fun if it was easy. Doug MacDonald CH-701 Scratch Builder 912 UL NW Ontario, Canada ========== -List" target="_blank">http://www.matronics.com/Navigator?RotaxEngines-List ========== http://forums.matronics.com ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== href="http://www.matronics.com/Navigator?RotaxEngines-List">http://www. matronics.com/Navigator?RotaxEngines-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________ Message 2 _____________________________________ Time: 04:13:10 AM PST US From: "Robert C Harrison" Subject: RE: RotaxEngines-List: Re: rough running at 3400 RPM and above Hi! I've not been following this thread but the electrical fuel pumps also have a very fine thimble filter in the intake end which needs VERY careful attention to remove it for inspection/cleaning and it is impossible to get a replacement filter .Returning this filter into its working location needs a very blunt instrument to push the filter into place from the bottom of the thimble shape taking care not to damage the gauze. Regards Bob Harrison. _____ From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Duncan & Ami McFadyean Sent: 08 July 2010 08:55 Subject: Re: RotaxEngines-List: Re: rough running at 3400 RPM and above There is also a filter in the mechanical fuel pump. Obviously there is no way of cleaning this. Only a fuel pressure test (measured downstream of the pump) will give a clue as to whether its blocked. Duncan McF. ----- Original Message ----- From: aoldman@xtra.co.nz Sent: Wednesday, July 07, 2010 9:55 AM Subject: Re: RotaxEngines-List: Re: rough running at 3400 RPM and above When you stopped the engine to check the plugs did you also check the fuel in the carb bowls. The fuel pump { or filter }may not be delivering sufficent fuel to keep it running at high RPM settings. Have you check the exhaust has not become obstructed while the engine was not being used , that problem can also become apparent at high RPM . Just some more things to check. Downunder MK111c ----- Original Message ----- From: Richard Girard Sent: Wednesday, July 07, 2010 3:02 PM Subject: Re: RotaxEngines-List: Re: rough running at 3400 RPM and above Have you checked all the pieces of the equalizer line between the two intake manifolds? Try checking the vacuum readings at the equalizer and then at the carb taps with the equalizer line connected to see if there's any gross difference. As long as you had the carbs off, did you pull the carb sockets and check them? I know you said they are recently replaced, but they're easy to check and it eliminates one more possible source of a leak. There was a bad batch a few years back that rotted out within a year. I couldn't see the cracks in mine until I got them off and used a strong light, then the cracks were obvious. What about the o-rings at the socket and those on the intake manifolds? Have you checked the diaphragms in the carb domes? You've had them out to raise the needle did you make sure the tab on the diaphragm is set in the slot in the carburetor body? Also, from the IPC, there are no o-ring seals on the throttle shafts? Have you miked them to see if the carb body is corroded or rotted out the throttle shaft bore? Personally, I wouldn't start messing with jetting until you've exhausted every possibility of a gross air leak. Rick Girard On Tue, Jul 6, 2010 at 8:57 PM, MacDonald Doug wrote: The saga continues... Tonight I pulled the carbs right off of the plane. I pulled them apart and this time got the float needles right out. There was a small chunk of silicone beside the needle in one of the carbs but after removing it and running the engine, there was little improvment if any. I was able to get it up to 4200 with the enrichener on but only the same old 3400 with the enrichener off. Other things I have tried is raising the needle one notch to full rich. This also made little to no difference. I stopped the engine while it was misfiring at 3400 RPM and pulled a couple of plugs. They were sooty white so I think we can say that this issue is definately a lean misfire. I read someplace in the parts manual that there are slightly larger main jets available when you run an air box. Since I have the original cone filters, I removed the airbox and ran it with them (also on the richest needle setting) and again the engine stumbles at about 3400 RPM. One thought I had tonight after all of this playing around is; is it possible that the throttle shaft o-rings could leak enough to cause this issue? I don't know that they are leaking but given that the carbs are over ten years old, it is possible. While I had the carbs apart I re-checked all of the other passages and found no buildup in any of them. Getting frustrating but this wouldn't be any fun if it was easy. Doug MacDonald CH-701 Scratch Builder 912 UL NW Ontario, Canada ========== -List" target="_blank">http://www.matronics.com/Navigator?RotaxEngines-List ========== http://forums.matronics.com ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== href="http://www.matronics.com/Navigator?RotaxEngines-List">http://www.matro nics.com/Navigator?RotaxEngines-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c href="http://www.matronics.com/Navigator?RotaxEngines-List">http://www.matro nics.com/Navigator?RotaxEngines-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________ Message 3 _____________________________________ Time: 05:38:24 AM PST US Subject: RotaxEngines-List: Re: 912ULS Recommended Oil From: "dashwood" i am in need of oil advice too . you can follow some of the more recent post by me. the latest is a report from my ame that the gearbox is toast after 400hrs. i took it in for inspection of a leak in the front seal. the history that i can get to is 1992 to 99 engine was in a box in georgia usa, not sure if pickled proper or not. then installed and used for 200hrs on amsoil semi 10/40 . then i purchased airplane and used amsoil for a short time then switched to the mobil mx4 as a rotax recommended oil. baced on the parts list i was given the case is fine :( the rest not so good. worn parts and gear tooth galling. my next question is if gearbox is so bad ????? about the engine. what oil to use? what oil not to use? -------- Ross Aalexander: CH701 driver 912ul 398tt Read this topic online here: http://forums.matronics.com/viewtopic.php?p=304153#304153 ________________________________ Message 4 _____________________________________ Time: 05:59:58 AM PST US From: "Thilo Kind" Subject: RotaxEngines-List: CHT temps Hi folks, in need for some advice. I'm flying a Zodiac CH 601 HDS with Rotax 912 UL. Engine parameters are monitored with an EIS. CHT temps were always around 100 F plus / minus a bit depending on OAT. Water temps in cruise are 150 F. Both CHT's were always the same with little to no fluctuation. That seemed a bit strange, so I recently disconnected the wire harness from the EIS and from the CHT and measured the cables. Everything seemed fine and I put it back to together. Now I observing basically the same CHT temps, but they fluctuate quite a bit - within a few seconds they might go up to 125 F and fall right back, etc. Anybody with an idea about the cause? Thanks Thilo -- GRATIS fr alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01 ________________________________ Message 5 _____________________________________ Time: 06:12:13 AM PST US Subject: RotaxEngines-List: Re: CHT temps From: "Roger Lee" A loose connection will cause this, and seeing that you just removed the wires that would be my guess. The connections on the CHT probe should be snug and not loose to move freely. It should be snug on the probe end. If you are really running 100F then that is too cold. Or did you mean 100C? What rpm are you cruising at, what are the oil temps and EGT's if you have this info. Typically water temp and CHT's are only a few degree spread, 50F is more than it should be. -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Repair Center 520-574-1080 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=304167#304167 ________________________________ Message 6 _____________________________________ Time: 06:15:37 AM PST US Subject: RotaxEngines-List: Re: 912ULS Recommended Oil From: "Roger Lee" read this about oils then you'll know why certain oils are better than others. -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Repair Center 520-574-1080 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=304168#304168 Attachments: http://forums.matronics.com//files/oil_comparison_638.pdf ________________________________ Message 7 _____________________________________ Time: 08:51:51 AM PST US From: MacDonald Doug Subject: RotaxEngines-List: Re: rough running at 3400 RPM and above Thank you for all of the suggestions. I'll be looking into these issues a little further this weekend. Yesterday I ordered a complete overhaul kit for both carbs. It's a little pricey but then everything will be new. This morning I ordered the Bing manual. I've probably spent more on the three gallons of 100LL I've burned troulbeshooting this issue than the cost of the manual. Anyway, all of this stuff should be here Monday or Tuesday so hopefully I'll be running correctly by mid next week. I'll keep you informed. Thanks again Doug MacDonald CH-701 NW Ontario, Canada ________________________________ Message 8 _____________________________________ Time: 10:45:43 AM PST US Subject: Re: RotaxEngines-List: Re: 912ULS Recommended Oil From: FLYaDIVE Ross: As from my reading on AMSOIL they are ALL 100% Synthetic. They are NOT advertised as a 50/50 blend. Many - Many years ago I did a study on model RC engines and ... Long story short --- 100% Synthetic is NOT the way to go. Synthetic is great for lubrication but that is only half the story. What oil MUST do is REMOVE the HEAT. Your petroleum based oils do that NOT the Synthetics. You also want to use something that is 20W 50. There has been millions of words written about automotive oil in aviation engines... I have heard some Good and Bad reports. The only thing that holds some... Not much water is: An aviation oil is designed with more ingredients to take care of the EP range of the oils. Aviation engines run at 65% to 75% power 95% of the time. Automotive engines run at 15% to 20% power 95% of the time. Much Less Load on automotive. So, that is where I believe the problem could have originated from. Barry On Thu, Jul 8, 2010 at 8:37 AM, dashwood wrote: > dashwoodlock@hotmail.com> > > i am in need of oil advice too . you can follow some of the more recent > post by me. the latest is a report from my ame that the gearbox is toast > after 400hrs. i took it in for inspection of a leak in the front seal. the > history that i can get to is 1992 to 99 engine was in a box in georgia usa, > not sure if pickled proper or not. then installed and used for 200hrs on > amsoil semi 10/40 . then i purchased airplane and used amsoil for a short > time then switched to the mobil mx4 as a rotax recommended oil. baced on > the parts list i was given the case is fine :( the rest not so good. worn > parts and gear tooth galling. my next question is if gearbox is so bad ????? > about the engine. what oil to use? what oil not to use? > > -------- > Ross Aalexander: CH701 driver 912ul 398tt > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=304153#304153 > > ________________________________ Message 9 _____________________________________ Time: 02:38:37 PM PST US From: Michael Woolson Subject: RotaxEngines-List: 582 oil Hi guy's I'm about to run the engine for the first time and would to know if anyone out there have feedback on what brand's they use and why they like them. - The aircraft is a Loehle 5151 mustang with duel carbs. - Thanks Mike Woolson Livermore CA. KLVK ________________________________ Message 10 ____________________________________ Time: 02:45:01 PM PST US From: Blumax008@aol.com Subject: Re: RotaxEngines-List: 582 oil Pennzoil or AMS...your choice. Been flying these 2 sicle suckers for nigh on 38 year you young whipper-snapper you! ________________________________ Message 11 ____________________________________ Time: 03:00:22 PM PST US Subject: Re: RotaxEngines-List: 582 oil From: FLYaDIVE Mike: Stick with Aviation Proven stuff... I happen to like Philips 20W-50 You can get that in AD or NON-AD The manufacture may recommend something... If they warranty the engine use what they recommend. As I posted before - NEVER USE A 100% SYNTHETIC OIL. Barry On Thu, Jul 8, 2010 at 5:38 PM, Michael Woolson wrote: > Hi guy's > I'm about to run the engine for the first time and would to know if anyone > out there have feedback on what brand's they use and why they like them. > > The aircraft is a Loehle 5151 mustang with duel carbs. > > Thanks > Mike Woolson > Livermore CA. KLVK > > * > > * > > ________________________________ Message 12 ____________________________________ Time: 03:56:04 PM PST US Subject: RotaxEngines-List: Re: 912ULS Recommended Oil From: "rampil" Barry, Are you sure you want to offer opinions on the care of $20k aircraft engines different from the factory, the service centers, and experienced mechanics based on your experience in rc engines. Not many RC engines have water cooled heads. Synthetic oils are preferred in Rotax 900 series engines in general and should not be used in the specific case of using AV Gas with lead. Rotax adds and deletes oils to the Service Letter based on testing and also on promotional/competitive reasons. Recently Mobil One for Rotaxwas introduced as a synthetic which does not sludge in the presence of tetraethyl lead. At SnF this year Rotax was highly promoting this oil as the best available. -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=304257#304257 ________________________________ Message 13 ____________________________________ Time: 05:36:55 PM PST US Subject: RotaxEngines-List: Re: 912ULS Recommended Oil From: "Roger Lee" Full synthetic or semi synthetics oils for a 4 stroke engine are well above a standard dino oil for performance and high stress situations. This has been demonstrated by many institutions. Personally I would never put a dino oil in a high performance, high compression, close tolerance and gearbox sharing situation engine like the Rotax. I tear into enough of them and seen enough pictures from Rotax themselves to keep me in the synthetics and out of the full dino oils. -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Repair Center 520-574-1080 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=304267#304267 ________________________________ Message 14 ____________________________________ Time: 07:52:48 PM PST US From: "dave" Subject: RE: RotaxEngines-List: Re: 912ULS Recommended Oil The other factor in Rotax recommendations is foaming. With the average system using only 3 liters of oil, foamed oil can easily enter the pressurized side of the engine. Air compresses, fluids don't. Air in the lifters causes collapsed lifters, loose pushrods that can then get bent and hammered rocker arms. Air in the main galleys results in poor oil flow to cam bearings and mains. Foam in the oil causes reduced pressure indications and a jumpy needle on an analog gage. I prefer the Mobil Racing (MX4T) but use Penzoil when stuck using 100LL such as flying in the western states where the autogas is unavailable or just inconvenient to transport. Dave -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of rampil Sent: Thursday, July 08, 2010 5:56 PM Subject: RotaxEngines-List: Re: 912ULS Recommended Oil Barry, Are you sure you want to offer opinions on the care of $20k aircraft engines different from the factory, the service centers, and experienced mechanics based on your experience in rc engines. Not many RC engines have water cooled heads. Synthetic oils are preferred in Rotax 900 series engines in general and should not be used in the specific case of using AV Gas with lead. Rotax adds and deletes oils to the Service Letter based on testing and also on promotional/competitive reasons. Recently Mobil One for Rotaxwas introduced as a synthetic which does not sludge in the presence of tetraethyl lead. At SnF this year Rotax was highly promoting this oil as the best available. -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=304257#304257 ------------------------------------------------------------------------------------- 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.