---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Sat 05/23/15: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:27 AM - Re: 912 rough running below 3000 rpm (David Weaver) 2. 01:29 PM - Re: 912 rough running below 3000 rpm (Flynn Elliott) 3. 10:04 PM - Re: 912 rough running below 3000 rpm (rampil) ________________________________ Message 1 _____________________________________ Time: 09:27:01 AM PST US From: David Weaver Subject: Re: RotaxEngines-List: 912 rough running below 3000 rpm I have seen the problem you have described.=C2- When a carb idle jet beco mes blocked, the engine will shake at RPM below 3,000.=C2- Then the float s of both carbs begin to bounce, which contributes to the engine running ro ugh (floats become incompetent).=C2- By removing the float bowls of both carbs you can remove the idle jet in each carb for inspection under a brigh t lite.=C2- I found a very small spec of fuel hose lining blocked a jet o n one of my carbs.=C2- Probably happened when I installed a carb fuel hos e on a barb fitting.Dave Weaver N912GR On Friday, May 22, 2015 2:52 PM, Flynn Elliott wrote: line.co.za> Good thought John Thanks -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of John Hauck Sent: 22 May 2015 08:57 PM Subject: RE: RotaxEngines-List: 912 rough running below 3000 rpm --> I run a single strand copper wire through them to insure they are clean. Copper won't scratch the jet. john h mkIII Titus, Alabama -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Flynn Elliott Sent: Friday, May 22, 2015 1:19 PM Subject: RE: RotaxEngines-List: 912 rough running below 3000 rpm --> Thanks John, will pull them out and double check Again . -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of John Hauck Sent: 22 May 2015 06:25 PM Subject: RE: RotaxEngines-List: 912 rough running below 3000 rpm --> Insure both idle jets are completely open. Over the years I have discovered a rough or no run 912ULS below 3000 rpm is idle jet related. Idle jet is extremely small.=C2- A tiny bit of trash makes a lot of diffe rence on fuel flow. For what it is worth. john h mkIII Titus, Alabama -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of flynn elliott Sent: Friday, May 22, 2015 11:12 AM Subject: RotaxEngines-List: 912 rough running below 3000 rpm Hi Guys, could really use some help with a 912s. After leaving my Foxbat for two months , she started up just fine as usual but ran as rough as hell untill 3000rpm and up where the motor runs smooth as silk. As always the fuel had been drained and fresh put in after the layup. We have since cleaned the carbs, put new float bowl gaskets, a fresh set of plugs and had my A P balance the carbs, which were real close anyway. The start up is instant as always has been, the mag drop is inconsistant, sometimes between 100 and 200=C2- and very rough below below 3000rpm yet back to its usual 50rpm drop above. Original plugs went back in and gave the same result. I flew for half an hour yesterday in the hope of clearing the problem but n o way, as I closed the throttle for landing we were back to a very rough motor. Any help would be more than appreciated. Thanks Flynn Read this topic online here: http://forums.matronics.com/viewtopic.php?p=442457#442457 ----- No virus found in this message. Checked by AVG - www.avg.com ----- No virus found in this message. Checked by AVG - www.avg.com - S - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ________________________________ Message 2 _____________________________________ Time: 01:29:37 PM PST US From: "Flynn Elliott" Subject: RE: RotaxEngines-List: 912 rough running below 3000 rpm Hi Dave, Thanks for your input, every one seems to be in the same mind over this issue. Will get on it asap and report back . Flynn Sent: 23 May 2015 06:26 PM Subject: Re: RotaxEngines-List: 912 rough running below 3000 rpm I have seen the problem you have described. When a carb idle jet becomes blocked, the engine will shake at RPM below 3,000. Then the floats of both carbs begin to bounce, which contributes to the engine running rough (floats become incompetent). By removing the float bowls of both carbs you can remove the idle jet in each carb for inspection under a bright lite. I found a very small spec of fuel hose lining blocked a jet on one of my carbs. Probably happened when I installed a carb fuel hose on a barb fitting. Dave Weaver N912GR On Friday, May 22, 2015 2:52 PM, Flynn Elliott wrote: Good thought John Thanks -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of John Hauck Sent: 22 May 2015 08:57 PM Subject: RE: RotaxEngines-List: 912 rough running below 3000 rpm --> I run a single strand copper wire through them to insure they are clean. Copper won't scratch the jet. john h mkIII Titus, Alabama -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Flynn Elliott Sent: Friday, May 22, 2015 1:19 PM Subject: RE: RotaxEngines-List: 912 rough running below 3000 rpm --> Thanks John, will pull them out and double check Again . -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of John Hauck Sent: 22 May 2015 06:25 PM Subject: RE: RotaxEngines-List: 912 rough running below 3000 rpm --> Insure both idle jets are completely open. Over the years I have discovered a rough or no run 912ULS below 3000 rpm is idle jet related. Idle jet is extremely small. A tiny bit of trash makes a lot of difference on fuel flow. For what it is worth. john h mkIII Titus, Alabama -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of flynn elliott Sent: Friday, May 22, 2015 11:12 AM Subject: RotaxEngines-List: 912 rough running below 3000 rpm Hi Guys, could really use some help with a 912s. After leaving my Foxbat for two months , she started up just fine as usual but ran as rough as hell untill 3000rpm and up where the motor runs smooth as silk. As always the fuel had been drained and fresh put in after the layup. We have since cleaned the carbs, put new float bowl gaskets, a fresh set of plugs and had my A P balance the carbs, which were real close anyway. The start up is instant as always has been, the mag drop is inconsistant, sometimes between 100 and 200 and very rough below below 3000rpm yet back to its usual 50rpm drop above. Original plugs went back in and gave the same result. I flew for half an hour yesterday in the hope of clearing the problem but no way, as I closed the throttle for landing we were back to a very rough motor. Any help would be more than appreciated. Thanks Flynn Read this topic online here: http://forums.matronics.com/viewtopic.php?p=442457#442457 ----- No virus found in this message. Checked by AVG - www.avg.com ----- No virus found in this message. C======================== No virus found in this message. Checked by AVG - www.avg.com 05/23/15 ________________________________ Message 3 _____________________________________ Time: 10:04:48 PM PST US Subject: RotaxEngines-List: Re: 912 rough running below 3000 rpm From: "rampil" Here's another thought. At mid range or less throttle, one of the carb slides may stick in the barrel, unbalancing the engine. Did you A&P try balancing down in the throttle range where you see the trouble? -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=442517#442517 ------------------------------------------------------------------------------------- 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.