---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Mon 08/04/14: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:12 PM - Low RPM on Takeoff??? (tmitton) 2. 11:21 PM - Re: Low RPM on Takeoff??? (David Joyce) ________________________________ Message 1 _____________________________________ Time: 05:12:08 PM PST US Subject: RotaxEngines-List: Low RPM on Takeoff??? From: "tmitton" Recently my 912ULS engine started only going to 5000rpm on takeoff with full throttle. Previously it always went directly to 5500rpm or so upon application of full power. Now it only goes above 5000rpm once it has been flying for a few minutes. Once flying it will still go to 5500+ even in a climb so it isn't like it is just the climbing load on take off that is holding it back. No changes have been made to the engine so I don't know what would cause the RPM drop. It is enough that takes offs now need 1000+ feet where as before 500-600ft was enough. There is definitely a noticeable difference. I have checked the carburetor linkages - full throw to the stops there. Drained the gas in case it was old and replaced it with fresh new gas - no change. Tried it with half a tank of 100LL to give it an octane boost - no change. Checked the spark plugs - still clean after only 25hrs of use. Nothing stuck on the rads. Oil topped up. So - any idea as to what might cause the drop in rpm? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=427986#427986 ________________________________ Message 2 _____________________________________ Time: 11:21:38 PM PST US From: "David Joyce" Subject: Re: RotaxEngines-List: Low RPM on Takeoff??? Don't know whether 912S works the same way as 914, but a leak of fuel/air from the carb fuel bowl will do just that on a 914. David Joyce On Mon, 4 Aug 2014 17:11:20 -0700 "tmitton" wrote: > > > Recently my 912ULS engine started only going to 5000rpm >on takeoff with full throttle. > > Previously it always went directly to 5500rpm or so upon >application of full power. Now it only goes above 5000rpm >once it has been flying for a few minutes. Once flying it >will still go to 5500+ even in a climb so it isn't like >it is just the climbing load on take off that is holding >it back. > > No changes have been made to the engine so I don't know >what would cause the RPM drop. It is enough that takes >offs now need 1000+ feet where as before 500-600ft was >enough. There is definitely a noticeable difference. > > I have checked the carburetor linkages - full throw to >the stops there. Drained the gas in case it was old and >replaced it with fresh new gas - no change. Tried it with >half a tank of 100LL to give it an octane boost - no >change. Checked the spark plugs - still clean after only >25hrs of use. Nothing stuck on the rads. Oil topped up. > > So - any idea as to what might cause the drop in rpm? > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=427986#427986 > > > > > > > >Un/Subscription, >http://www.matronics.com/Navigator?RotaxEngines-List >Forums! >Admin. > > > ------------------------------------------------------------------------------------- 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.