---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Thu 03/13/08: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:37 AM - Re: Re: 912 with low RPM--- new vibration problem (Thom Riddle) 2. 06:34 AM - Re: Re: 912 with low RPM--- new vibration problem (Bear Creek Aviation) 3. 10:06 AM - Re: Re: 912 with low RPM--- new vibration problem (Les Goldner) 4. 03:50 PM - Re: Re: 912 with low RPM--- new vibration problem (Rich & Sandy Schultz) 5. 06:02 PM - Re: Re: 912 with low RPM--- new vibration problem (Noel Loveys) 6. 10:16 PM - AW: Re: 912 with low RPM--- new vibration problem (Roger Lee) 7. 10:26 PM - Re: 912 with low RPM--- new vibration problem (Roger Lee) ________________________________ Message 1 _____________________________________ Time: 05:37:03 AM PST US From: Thom Riddle Subject: Re: RotaxEngines-List: Re: 912 with low RPM--- new vibration problem Les, A couple other ideas: 1) Have you checked the spark plugs to see if one (or more) of the cylinders is running richer or leaner than the rest? If this is the case, let us know and I'll tell you about the solution that took me months to finally find and fix. It was nothing anyone could think of, including the experts at Lockwood. If not, then no need to go into the long story. 2) When you disassembled the carbs for jet cleaning etc. did you get the cylinder and diaphragm back in the right direction? I didn't once and the result was rough running in the mid range. Thom in Buffalo ________________________________ Message 2 _____________________________________ Time: 06:34:23 AM PST US From: Bear Creek Aviation Subject: Re: RotaxEngines-List: Re: 912 with low RPM--- new vibration problem We had a problem with a 582 that was similar. Two things, first there was crud way up in the jet almost impossible to see without looking thru it at a bright light, secondly the gas was "decomposing" and no sooner had we cleaned it out it had started compacting some sort of white material back into the idle jets. Incidentally, I would never eliminate any variable, prop, engine, motormount etc, until it was proven serviceable regardless of it's age/hours Good luck, Terry. ________________________________ Message 3 _____________________________________ Time: 10:06:43 AM PST US From: "Les Goldner" Subject: RE: RotaxEngines-List: Re: 912 with low RPM--- new vibration problem Thom, I changed the plugs at 20-hours after "feeling" the problem. They all looked the same. I also pulled the new plugs once to check cylinder pressure.. Again, they were all the same. I never attempted to pull apart the tops of the carbs, so I didn't run into problems putting back cylinders & diaphragms. I just pulled the bowls and the jets for cleaning (which they didn't need). Thanks for trying to help, Les > -----Original Message----- > From: owner-rotaxengines-list-server@matronics.com > [mailto:owner-rotaxengines-list-server@matronics.com] On > Behalf Of Thom Riddle > Sent: Thursday, March 13, 2008 5:34 AM > To: rotaxengines-list@matronics.com > Subject: Re: RotaxEngines-List: Re: 912 with low RPM--- new > vibration problem > > --> > > Les, > > A couple other ideas: > 1) Have you checked the spark plugs to see if one (or more) > of the cylinders is running richer or leaner than the rest? > If this is the case, let us know and I'll tell you about the > solution that took me months to finally find and fix. It was > nothing anyone could think of, including the experts at > Lockwood. If not, then no need to go into the long story. > 2) When you disassembled the carbs for jet cleaning etc. did > you get the cylinder and diaphragm back in the right > direction? I didn't once and the result was rough running in > the mid range. > > Thom in Buffalo > > Photoshare, and much much more: > > ________________________________ Message 4 _____________________________________ Time: 03:50:33 PM PST US From: "Rich & Sandy Schultz" Subject: RE: RotaxEngines-List: Re: 912 with low RPM--- new vibration problem Did you check the spark gap on each plug? Is the vibration the same with each mag alone? Worse together? -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Les Goldner Sent: Thursday, March 13, 2008 12:04 PM Subject: RE: RotaxEngines-List: Re: 912 with low RPM--- new vibration problem Thom, I changed the plugs at 20-hours after "feeling" the problem. They all looked the same. I also pulled the new plugs once to check cylinder pressure.. Again, they were all the same. I never attempted to pull apart the tops of the carbs, so I didn't run into problems putting back cylinders & diaphragms. I just pulled the bowls and the jets for cleaning (which they didn't need). Thanks for trying to help, Les > -----Original Message----- > From: owner-rotaxengines-list-server@matronics.com > [mailto:owner-rotaxengines-list-server@matronics.com] On > Behalf Of Thom Riddle > Sent: Thursday, March 13, 2008 5:34 AM > To: rotaxengines-list@matronics.com > Subject: Re: RotaxEngines-List: Re: 912 with low RPM--- new > vibration problem > > --> > > Les, > > A couple other ideas: > 1) Have you checked the spark plugs to see if one (or more) > of the cylinders is running richer or leaner than the rest? > If this is the case, let us know and I'll tell you about the > solution that took me months to finally find and fix. It was > nothing anyone could think of, including the experts at > Lockwood. If not, then no need to go into the long story. > 2) When you disassembled the carbs for jet cleaning etc. did > you get the cylinder and diaphragm back in the right > direction? I didn't once and the result was rough running in > the mid range. > > Thom in Buffalo > > Photoshare, and much much more: > > ________________________________ Message 5 _____________________________________ Time: 06:02:10 PM PST US From: "Noel Loveys" Subject: RE: RotaxEngines-List: Re: 912 with low RPM--- new vibration problem As soon as I saw the reference to white material the questions came to mind 1. what are your tanks made of?? 2. Are you flying with ethanol fuel? 3. Do you premix? Noel -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Bear Creek Aviation Sent: Thursday, March 13, 2008 12:01 PM Subject: Re: RotaxEngines-List: Re: 912 with low RPM--- new vibration problem We had a problem with a 582 that was similar. Two things, first there was crud way up in the jet almost impossible to see without looking thru it at a bright light, secondly the gas was "decomposing" and no sooner had we cleaned it out it had started compacting some sort of white material back into the idle jets. Incidentally, I would never eliminate any variable, prop, engine, motormount etc, until it was proven serviceable regardless of it's age/hours Good luck, Terry. ________________________________ Message 6 _____________________________________ Time: 10:16:24 PM PST US Subject: RotaxEngines-List: AW: Re: 912 with low RPM--- new vibration problem From: "Roger Lee" Hi Thilo, Good advice at rpm's below 3500. The enricher does not play a part though above 3500rpm. Certainly not above 4000. If it ran rough below 3500 then the enricher could be the culprit, but then it should smooth out at cruise rpm. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=169751#169751 ________________________________ Message 7 _____________________________________ Time: 10:26:16 PM PST US Subject: RotaxEngines-List: Re: 912 with low RPM--- new vibration problem From: "Roger Lee" Hi Les, Doesn't sound like a carb issue anymore since you checked that. You checked the mags (ignition coils), balanced the carb and checked for clean carbs. It kind of only leaves one thing. When you rule out everything else then what ever is left is probably the culprit. My Warp Drive was out of balance since day one. Has any little nut, bolt or part been changed from the prop hub forward? You still need to rule out static and dynamic balance. Until the last two things are done you could chase a ghost for ever. I know you don't want to hear that, but what else is left. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=169752#169752 ------------------------------------------------------------------------------------- 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.