---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Mon 06/18/12: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:05 AM - Re: Rotax 912 ul engine problems (fgoggio@yahoo.com) 2. 03:49 AM - Re: RotaxEngines-List Digest: 17 Msgs - 06/17/12 (James Meade) 3. 03:53 AM - Re: RotaxEngines - Rotax 912 ul engine problems (MacDonald Doug) 4. 04:17 AM - Re: Rotax 912 ul engine problems (Thom Riddle) 5. 04:46 AM - Re: Rotax 912 ul engine problems (Catz631@aol.com) 6. 06:16 AM - Re: Rotax 912 ul engine problems (Scott DeMeyer) 7. 07:24 AM - 912ul miss (egp8111) 8. 07:29 AM - Re: 912ul miss (Blumax008@aol.com) 9. 01:00 PM - Re: Rotax 912 ul engine problems (Roger Lee) 10. 01:07 PM - Re: 912ul miss (Roger Lee) 11. 01:46 PM - Re: Re: Rotax 912 ul engine problems (Craig Payne) 12. 02:03 PM - Re: Rotax 912 ul engine problems (Roger Lee) 13. 02:47 PM - Re: Re: RotaxEngines-List Digest: 17 Msgs - 06/17/12 (=?ISO-8859-1?Q?J=F3hann_J=F3hannsson?=) 14. 03:37 PM - Re: Rotax 912 ul engine problems (Gtblu) ________________________________ Message 1 _____________________________________ Time: 03:05:18 AM PST US From: "fgoggio@yahoo.com" Subject: Re: RotaxEngines-List: Rotax 912 ul engine problems V2UgaGF2ZSB0YmUgcmVndWxhciBnZWFyIGJveC4yLDI3LnRiZSB3YXkgd2UgZm91bmQgaXQgd2Ug dG9vayB0aGUgcHJvcCBvZiBhbmQgcmFuIHRoZSBlbmdpbmUuaWYgeW91IHRoaXMgYmUgc3VyZSB0 byBkbyB0aGlzIGF0IGxvdyBycG0uIEZyYW5rCgpTZW50IGZyb20gbXkgVmVyaXpvbiBXaXJlbGVz cyA0RyBMVEUgRFJPSUQKCi0tLS0tT3JpZ2luYWwgbWVzc2FnZS0tLS0tCkZyb206ICJKw7NoYW5u IErDs2hhbm5zc29uIiA8am9laW5nNzAxQHNpbW5ldC5pcz4KVG86IHJvdGF4ZW5naW5lcy1saXN0 QG1hdHJvbmljcy5jb20KU2VudDogU3VuLCBKdW4gMTcsIDIwMTIgMjI6NDE6NDcgRURUClN1Ympl Y3Q6IFJlOiBSb3RheEVuZ2luZXMtTGlzdDogUm90YXggOTEyIHVsIGVuZ2luZSBwcm9ibGVtcwoK SGVsbG8gRnJhbmsuCgpUaGFuayB5b3UgdmVyeSBtdWNoIGZvciB0aGF0IGluZm9ybWF0aW9uLiBU aGlzIGlzIHNvbWV0aGluZyB3ZSB3aWxsICAKZGVmaW5pdGVseSBsb29rIGludG8uIFdoYXQga2lu ZCBvZiBnZWFyIGJveCBkaWQgeW91IGhhdmU/IFRoZSBzdGFuZGFyZCAgCjIsMjcgb3Igd2l0aCB0 aGUgc2xpcHBlciBjbHV0Y2g/CgpCZXN0IHJlZ2FyZHMsCkpvaGFubiBHLgpJY2VsYW5kLgoKCk9u IDE4LjYuMjAxMiwgYXQgMDE6MTYsIGZnb2dnaW9AeWFob28uY29tIHdyb3RlOgoKPiBKb2hhbi5p IGhhZC4gQSBwcm9ibGVtIGxpa2UgeW91IGFyZSBoYXZpbmcgb24gYSBvbGRlciBtb2RlbCA5MTIg dGhlICAKPiBjYXJicy4gV2VyZSByZWJ1aWx0IHRocmVlIHRpbWVzIGJ5IHJvdGF4IHJlcGFpcm1h bi4gQ2FyYnMgIAo+IHN5Y3RlZC5vdmVyIGFuZCBvdmVyLmZpbmRseSBwdXQgbmV3IGNhcmJzIG9u LnN0aWxsIGhhZCAgCj4gcHJvYmxlbXMucmVwbGFjZWQuIGlnbml0aW9uIG1vZGVhbHMuc3RpbGwg aGFkLnByb2JsZW1zLmFsbCBzdGFydGVkICAKPiBsaWxlIHlvdXJzLmZpbmRseSBmb3VuZCB0aGUg cHJvYmxlbSB0byBiZSBpbiB0aGUgcmVkcml2ZSAgCj4gc3lzdGVtLm5lZWRlZCB0byBiZSByZSBi dWlsdC5wcm9ibGVtcyB3ZW10IGF3YXkubWluZSBzdGFydGVkIGluICAKPiBmbGdqdCBhdCA0NTAw IHJwbS5kcm92ZSB0aGUgcm90YXggbWFuIGNyYXp5LnN3b3JlIGl0IGNvdWxkIG5vdCBiZSAgCj4g dGhlIHJlZHJpdmUKPiBCdXQgd2FzLi5zcG1ldGhpbmcgZWxzZSB0byB0aGluayBhYm91dC5nb29k IGx1Y2sKPiBGcmFuayBnb2dnaW8uIFdpbG1pbmd0b24uIE5jCj4KPiBTZW50IGZyb20gbXkgVmVy aXpvbiBXaXJlbGVzcyA0RyBMVEUgRFJPSUQKPgo+Cj4gLS0tLS1PcmlnaW5hbCBtZXNzYWdlLS0t LS0KPiBGcm9tOiAiSsOzaGFubiBKw7NoYW5uc3NvbiIgPGpvZWluZzcwMUBzaW1uZXQuaXM+Cj4g VG86IHJvdGF4ZW5naW5lcy1saXN0QG1hdHJvbmljcy5jb20KPiBTZW50OiBTdW4sIEp1biAxNywg MjAxMiAyMDo0Mjo0NyBFRFQKPiBTdWJqZWN0OiBSZTogUm90YXhFbmdpbmVzLUxpc3Q6IFJvdGF4 IDkxMiB1bCBlbmdpbmUgcHJvYmxlbXMKPgo+Cj4KPiBUaGFuayB5b3UgVmljLgo+Cj4gVGhhdCBo YXMgYmVlbiBkb25lIGFmdGVyIGV2ZXJ5IGFkanVzdG1lbnQgb2YgdGhlIGNhYmxlcyBhbmQgbWFu eSAgCj4gbW9yZS4gRXZlcnl0aGluZyBpcyBpbiB2ZXJ5IGdvb2Qgc3luYyBhbGwgdGhyb3VnaC4g V2UgYXJlIHN0aWxsICAKPiB0cnlpbmcgdG8gZmluZCBvdXQgaWYgdGhlcmUgaXMgYW55IGJpbmRp bmcgaW4gdGhlIGNhcmIgdGhyb3R0bGUgIAo+IHZhbHZlLiBXZSB3aWxsIGNoYW5nZSBvdXQgdGhl IGNhcmJzIHRoaXMgd2VlayBhbmQgZmluZCBvdXQgdGhlbi4KPgo+IFRoYW5rcwo+IEpvaGFubiBH Lgo+IEljZWxhbmQuCj4gT24gMTguNi4yMDEyLCBhdCAwMAo ________________________________ Message 2 _____________________________________ Time: 03:49:02 AM PST US Subject: RotaxEngines-List: Re: RotaxEngines-List Digest: 17 Msgs - 06/17/12 From: "James Meade" What happens when you do a mag check when the engine is running rough? If you have CHT or EGT gaugges, what are they showing when running rough? What happens aboute the rough onset altitude, or do you get it above that? The engine smooths out by itself when running at lower altitude? Does the roughness correspond with how hard the engine is worked, such as on a hard climb as opposed to an easy climb? What happens if you climb at WOT through the normal onset altitude, or do you already? ________________________________ Message 3 _____________________________________ Time: 03:53:25 AM PST US From: MacDonald Doug Subject: RotaxEngines-List: Re: RotaxEngines - Rotax 912 ul engine problems I say this every time someone has a rough running engine.- =0A-=0ACheck to make sure the-enrichener arms-are closing all the way.- =0AIt is counter intuitive, but on a Bing carb, a partially open enrichener acts lik e =0Aan air bleed-at higher RPM and creates a lean condition and thus rou gh =0Arunning.- I got this from Dean Vogul from Lockwood and it fixed my problems =0Aduring- initial installation of my 80hp rotax.- I was exper iencing roughness and =0Aloss- of power at 3600-4200 RPM and above-unti l I adjusted my enrichener =0Acable to give me complete closure.The arms- don't have to be off the stops=0Amuch to create a problem.=0A-=0ADoug M =0ACH-701, 912UL=0ANW Ontario, Canada=0A=0A=0ATime: 06:21:34 AM PST US=0AFr om: =?ISO-8859-1?Q?J=F3hann_J=F3hannsson?= =0A Subject: RotaxEngines-List: Rotax 912 ul engine problems=0A=0A=0AHello list members.=0A=0AWe really need your- expert help regarding a Rotax 912 ul 80 hp engine- =0Aproblem my friend has been dealing with for the past- three years or- =0Aever since he bought the plane.=0A=0AMy friend bought this- Kitfox II aprox. 1990 model from USA and has- =0Abeen trying to s olve a rough running engine problem, and is about to- =0Agive up on the p roject.=0A=0AHere is the symptoms:=0A=0AEngine starts perfectly and runs on both mags with a drop within 100- =0Arpm. When airborne the rough runnin g starts around 3500-4500.- =0AEverything shakes very violently and aircr aft looses altitude. Most- =0Aoften you can give it full power to continu e flying, but when power is- =0Areduced, the shaking starts again. ________________________________ Message 4 _____________________________________ Time: 04:17:25 AM PST US Subject: RotaxEngines-List: Re: Rotax 912 ul engine problems From: "Thom Riddle" One thing I have found to cause rough running is poor connection between the spark plug wires and spark plug connector/cap. I've run across this several times. Make sure all are screwed in all the way clock-wise. After the first time I encountered this, I always check them on each condition inspection and mark the intersection with torque-seal or equivalent so they can be visually checked in the future. -------- 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=375972#375972 ________________________________ Message 5 _____________________________________ Time: 04:46:29 AM PST US From: Catz631@aol.com Subject: Re: RotaxEngines-List: Rotax 912 ul engine problems Johann, As Frank mentioned ,we too had a similar problem in a Paradise P-1. It would be rough in mid range.It was silky smooth so long as full power was applied (as in climbout) but upon power reduction the roughness would start and the airplane would vibrate like hell ! At one point during troubleshooting, I even shut the engine down and glided the airplane thru various speeds to see if it was airframe related ...it wasn't. It drove us nuts trying to find it. We changed props,tightened mounts,checked/synced carbs,etc,etc. Finally we sent the gearbox off to Lockwood for a re shim/rebuild as a last resort and that did it ! The engine did not have that much time and I would have sworn that was not the problem but it fixed it ! My Kitfox had a similar problem but I was able to fix it by replacing the throttle cables as one of them was apparently slightly sticking at mid range throwing the carbs out of balance. Check the "swivel" nuts on the carbs for sticking also. That is my two cents. Good luck !! Dick Maddux Milton,Fl ________________________________ Message 6 _____________________________________ Time: 06:16:28 AM PST US From: Scott DeMeyer Subject: Re: RotaxEngines-List: Rotax 912 ul engine problems Same exact problem here. Rebuilt carbs several times and changed many ignition components and nothing worked. After months of troubleshooting I gave up and flew the plane to a Rotax dealer. He rebuilt the gearbox and the problem went away. I had about 500 hours on the gearbox, 80HP Rotax. ________________________________ ________________________________ Message 7 _____________________________________ Time: 07:24:46 AM PST US Subject: RotaxEngines-List: 912ul miss From: "egp8111" I know this issue has been worked over a few times on the forum but I cant seem to find anything that matches my situation. Here's the deal, the 912 starts fine after warm up on the initial mag check it has about a 150-200 rpm drop on either mag at 4000 rpm. In flight it has an occasional miss at 5000rpm, some more notable than others. It also runs rough between 3000 and 4000 rpm not missing just rough feeling. After I land I can check the mags again and they only have a drop of about 50 rpm on either side. I've pneumatically balanced the carbs and they are dead on at 2500 rpm. The carbs have been cleaned and adjusted. new plugs etc. Also today I flew through a very light rain shower and the engine began to run notably rough at 5000rpm. After I left the area of rain it cleared up. Carb ice ? I do not have the carb heat box installed. Any ideas? Thanks EG Read this topic online here: http://forums.matronics.com/viewtopic.php?p=375987#375987 ________________________________ Message 8 _____________________________________ Time: 07:29:58 AM PST US From: Blumax008@aol.com Subject: Re: RotaxEngines-List: 912ul miss Possible leads. Tie it down or chock it good in a dark hangar at night and see if you see any fireworks are visible from the spark plug leads. May be breaking down at higher rpms or causing occasional trouble. Just a guess. In a message dated 6/18/2012 10:24:54 A.M. Eastern Daylight Time, egp8111@aol.com writes: --> RotaxEngines-List message posted by: "egp8111" I know this issue has been worked over a few times on the forum but I cant seem to find anything that matches my situation. Here's the deal, the 912 starts fine after warm up on the initial mag check it has about a 150-200 rpm drop on either mag at 4000 rpm. In flight it has an occasional miss at 5000rpm, some more notable than others. It also runs rough between 3000 and 4000 rpm not missing just rough feeling. After I land I can check the mags again and they only have a drop of about 50 rpm on either side. I've pneumatically balanced the carbs and they are dead on at 2500 rpm. The carbs have been cleaned and adjusted. new plugs etc. Also today I flew through a very light rain shower and the engine began to run notably rough at 5000rpm. After I left the area of rain it cleared up. Carb ice ? I do not have the carb heat box installed. Any ideas? Thanks EG Read this topic online here: http://forums.matronics.com/viewtopic.php?p=375987#375987 ________________________________ Message 9 _____________________________________ Time: 01:00:36 PM PST US Subject: RotaxEngines-List: Re: Rotax 912 ul engine problems From: "Roger Lee" Hi All, Gearbox's can certainly cause engine roughness, but I personally find the owners with Vernier type throttle cables to have more issues than others. The thicker wire to these type cables causes them to slightly stick in the sheath and when you operate the throttle one carb won't go back to exactly the same place. This makes one side of the engine try to run at let's say 5000 rpm while the other side tries to run at 5300 rpm. This opposing action makes things rough and not good for the long term health of the engine. This can make the carb sync procedure an headache too. -------- 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=376009#376009 ________________________________ Message 10 ____________________________________ Time: 01:07:28 PM PST US Subject: RotaxEngines-List: Re: 912ul miss From: "Roger Lee" Hi EGP, What are the plugs gapped at? They should be between .023 - .027. The wider gap for the hotter months. If the gap is too narrow especially in the summer you will get bigger mag drops and possible roughness. The second item is 2500 rpm is too low to do a very good balance. If you balance at 2500 and then run the rpm up to 4000 you will find that they will be off again. 2500 is too close to the idle circuit range and just doesn't flow enough fuel/air to get set up well. Check the plug gaps, apply the thermal conducting paste and not anti seize and then re-balance the carbs at 3500-4000. I would bet your engine will run even smoother. Depending on how your air cleaner is set up you may have taken on a little water, but no big deal as it usually runs through the system especially with 91 oct with ethanol. -------- 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=376011#376011 ________________________________ Message 11 ____________________________________ Time: 01:46:30 PM PST US From: "Craig Payne" Subject: RE: RotaxEngines-List: Re: Rotax 912 ul engine problems > The thicker wire to these type cables causes them to slightly stick in the sheath and when you operate the throttle one carb won't go back to exactly the same place. Are you referring to vernier throttles where the cables spit at the throttle. McFarLane makes this one: http://www.mcfarlane-aviation.com/Details.aspx?Article=199 I don't see how what you are describing could happen with a conventional vernier throttle where there is only a single cable that connects to an external splitter. -- Craig ________________________________ Message 12 ____________________________________ Time: 02:03:00 PM PST US Subject: RotaxEngines-List: Re: Rotax 912 ul engine problems From: "Roger Lee" Hi Craig, Just like that one. What happens is the sheath is metal on the inside and some times they get a slight corrosion and or some throttle setups have a little too much bend in one cable. It only takes about 1/16" with a little friction in a long cable with too tight a bend to cause the cable to not go back exactly to the same position. If you have a cable setup with small 1mm- 1.2mm cable then the springs on the carbs will almost always pull the cables back exactly to the same place every time. With a thick cable with a little bend the springs sometimes don't have quite enough tension to pull every last little bit of cable taught. The guys with the springs on the opposite side of the throttle arm that pull the cable back to idle cab be at times even worse. This condition will show up in a carb sync. Sync the carbs and then pull them back and forth 3-4 times and they should go back to where you set them the first time. If they seem to keep getting out of adjustment and you have a Vernier cable then you know what the issue is. I use my finger on the throttle arms to make sure the Vernier type cable always comes completely back out and make sure any little friction isn't a player in the sync job. -------- 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=376025#376025 ________________________________ Message 13 ____________________________________ Time: 02:47:10 PM PST US From: =?ISO-8859-1?Q?J=F3hann_J=F3hannsson?= Subject: Re: RotaxEngines-List: Re: RotaxEngines-List Digest: 17 Msgs - 06/17/12 Hello James. My friend did not dare do the mag check during this situation. The plan was to try it the next flight. EGT show the same temp. CHT analog meters not very steady to judge any difference. We have not tried climbing to an altitude higher than 1500 feet. Does not seem to change during climb or when under hard work. Last time we did the test, the plane climbed almost 1400 feet/min and with no hesitation. Roughness started when we leveled off and reduced the throttle below 5000 rpm. Thank you for your help. Johann G. Iceland. On 18.6.2012, at 10:48, James Meade wrote: > > > > What happens when you do a mag check when the engine is running > rough? If you have CHT or EGT gaugges, what are they showing when > running rough? What happens aboute the rough onset altitude, or do > you get it above that? The engine smooths out by itself when > running at lower altitude? Does the roughness correspond with how > hard the engine is worked, such as on a hard climb as opposed to an > easy climb? What happens if you climb at WOT through the normal > onset altitude, or do you already? > > ________________________________ Message 14 ____________________________________ Time: 03:37:45 PM PST US Subject: RotaxEngines-List: Re: Rotax 912 ul engine problems From: "Gtblu" Hi Johanne, I had a vibration problem at similar revs to you (5000) but not as bad in a 912uls. Having tried everything on the engine and gearbox I focused on the prop (thanks to Roger). It turned out to be the bolt lengths on the prop were too long by a fraction of a millimeter thus torquing the bolts to the end of their thread. Different atmospheric conditions allowed the prop hub to contract and expand, making the problem intermittent. A new set of correct length bolts solved the problem, however a whole new prop was fitted which in fact showed every prop/engine combination has its own vibration band, NOW being at about 4200 revs. Thats another topic! Cheers Geoff Bell Read this topic online here: http://forums.matronics.com/viewtopic.php?p=376037#376037 ------------------------------------------------------------------------------------- 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.