---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Tue 01/29/08: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:10 AM - Re: Throttle Cables sticking (Jack Kuehn) 2. 09:16 AM - Re: Throttle Cables sticking (Roger Lee) 3. 02:49 PM - Carb Heat with 912ULS (Jeffrey A Beachy) 4. 03:44 PM - Re: Carb Heat with 912ULS (Joe and Joan Kimbell) 5. 03:44 PM - Re: Carb Heat with 912ULS (george may) 6. 05:12 PM - Re: Carb Heat with 912ULS (Evan Gardiner) 7. 07:16 PM - Re: Re: Throttle Cables sticking (Dave) ________________________________ Message 1 _____________________________________ Time: 08:10:34 AM PST US From: "Jack Kuehn" Subject: Re: RotaxEngines-List: Throttle Cables sticking Not sure if I am using the same type of twisted cable as you are, but when the cables were new I took the cable out of the housing and sprayed it down with a silicone lubricant and made sure it was clean. I inspect them now every 50 hours and no problems. Could your bowing cable just be sticky? Jack On Jan 28, 2008 9:53 PM, Rich & Sandy Schultz wrote: > > > I am looking to see what others have done to prevent throttle cable bowing > of the twisted wire used in most throttle cables. I have a 914 installed on > a Europa and am having problems with one of the cables wanting to bow in the > throttle box and not allowing me to get full power. The throttle springs are > not strong enough to pull the cable and keep it in tension all the time. On > the Europa form others have talked about going to a solid cable .055 or .078 > SS piano wire. I have some concerns about the carburetor attachment point > producing a stress crack and failing under the vibration. I am interested to > hear what others have done? > > ________________________________ Message 2 _____________________________________ Time: 09:16:36 AM PST US Subject: RotaxEngines-List: Re: Throttle Cables sticking From: "Roger Lee" Here are a couple of things to do. 1. Use cable housing that has the plastic lining in it and not just plain steel lining. It allows the cable to move within the sheath smoothly and doesn't rust or develop rough spots. 2. Do like Jack said and remove the cable and use some cable lube 3. Step down a cable size to allow more room in the cable housing to move and not bind. On many planes trying to use 1/16" cable size is too big depending on the routing and turns that are made with the throttle cable. My cable in my CT is only 3/64" or 1.2mm. This is because it goes around a 1 1/4" size pulley and needs to be able to make the bend and be very flexible. Using the smaller size cable will allow your carb springs to work better and do their job. Use 7x7 or 7x19 cable. 7x19 is a little more flexible than 7x7. 4. Lube the throttle quadrant if you have one and make sure it moves freely. If it were me I would do all the above and then the throttle should be very smooth in its operation. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=161109#161109 ________________________________ Message 3 _____________________________________ Time: 02:49:35 PM PST US Subject: RotaxEngines-List: Carb Heat with 912ULS From: Jeffrey A Beachy I have a Rotax 912ULS with the Rotax airbox. My cold air is supplied via a NACA inlet on the cowl then through a filter and on to the airbox. Carb heat is via a flap in the airbox which pulls unfiltered air from a muffler cowl to the airbox. I understand that the 912 series is not prone to icing, but I cannot find anything in the Rotax literature offering suggested use of carb heat. So, experts, when do I use carb heat with my 912ULS? Only if engine is running rough and icing is suspected? In landing patterns like a Cub? All those using the Rotax airbox with a 912, I would appreciate your experience and suggestions. Thanks! Jeff Beachy Zenith CH701 ________________________________ Message 4 _____________________________________ Time: 03:44:27 PM PST US From: Joe and Joan Kimbell Subject: RE: RotaxEngines-List: Carb Heat with 912ULS Jeff, I have the carb heat and having used it close to two hundred times, I did indeed have ice one time. That happened to be during a time when I wa s doing stalls and slow flight. I live in very high humidity Fl. so on do wnwind at slightly reduced rpm i pull on Carb heat to see if there are any problems. so far none at that point on final I push in so i will get full r pm if needed. Joe > To: rotaxengines-list@matronics.com> Date: Tue, 29 Jan 2008 17:45:41 -050 0> Subject: RotaxEngines-List: Carb Heat with 912ULS> From: beachyjeff@juno ff@juno.com>> > I have a Rotax 912ULS with the Rotax airbox. My cold air is supplied via> a NACA inlet on the cowl then through a filter and on to the airbox. Carb> heat is via a flap in the airbox which pulls unfiltered air from a> muffler cowl to the airbox. I understand that the 912 series is not prone> to icing, but I cannot find anything in the Rotax literature offeri ng> suggested use of carb heat. So, experts, when do I use carb heat with m y> 912ULS? Only if engine is running rough and icing is suspected? In> land ing patterns like a Cub? All those using the Rotax airbox with a 912,> I wo uld appreciate your experience and suggestions. Thanks!> > Jeff Beachy> Zen -======================== ========> > > ________________________________ Message 5 _____________________________________ Time: 03:44:40 PM PST US From: george may Subject: RE: RotaxEngines-List: Carb Heat with 912ULS Jeff-- I use the carb heat on my Rotax for all landings, slow flight and if I su spect carb icing. George May 601XL 912s> To: rotaxengines-list@matronics.com> Date: Tue, 29 Jan 2008 17: 45:41 -0500> Subject: RotaxEngines-List: Carb Heat with 912ULS> From: beach > > I have a Rotax 912ULS with the Rotax airbox. My c old air is supplied via> a NACA inlet on the cowl then through a filter and on to the airbox. Carb> heat is via a flap in the airbox which pulls unfil tered air from a> muffler cowl to the airbox. I understand that the 912 ser ies is not prone> to icing, but I cannot find anything in the Rotax literat ure offering> suggested use of carb heat. So, experts, when do I use carb h eat with my> 912ULS? Only if engine is running rough and icing is suspected ? In> landing patterns like a Cub? All those using the Rotax airbox with a 912,> I would appreciate your experience and suggestions. Thanks!> > Jeff B =============> > > _________________________________________________________________ Helping your favorite cause is as easy as instant messaging.-You IM, we g ive. ________________________________ Message 6 _____________________________________ Time: 05:12:46 PM PST US From: "Evan Gardiner" Subject: Re: RotaxEngines-List: Carb Heat with 912ULS Hi Jeff, good question! There is certainly a divergence of opinion about the risk of carb icing with the Rotax 912 series. After suffering 3 forced landings (2 with the prop stopped!) with carb icing I decided it was time to do something about it. I fly an MCR 01 ULC (Ban-Bi) and the many, mainly European owners of this marque do not seem to be affected by carb icing. I live in New Zealand and it is a well established fact that our particular weather conditions do predispose to carb icing. Most 912 installations here do have some sort of carb heat provision - particularly if the carb. intake air is sourced from a ram air intake outside the engine cowl. Installations where the engine intake air temp is the same as the ambient air temp found within a tightly cowled engine compartment usually minimises the risk of carb icing even here in NZ. I have fitted a similar carb heat system as you and it works ok. If I was building another aircraft I would fit the system that has hot radiator water circulating through a jacket around the carb air intake. Fit it and forget about when you need to use it as it is on all the time with no significant power loss. To get back to your question though, in my experience with this sort of carb heat set up you need to prevent carb ice forming rather than wait till the engine starts running rough and then applying carb heat. Similar to GA best practise. In my set-up carb heat is not that efficient that I would rely on it melting a big ice build up before the engine quits. If the engine starts to run rough best to go to full power for a period, apply carb heat and leave it on for the rest of your flight. The best thing I did on my aircraft was to velcro on to my instrument panel an inexpensive indoor/outside digital temperature guage. One sensor is poked into the carb airbox which gives me OAT and the other sensor is RTVd on to the thoat area of the carb body. This probe will tell me when carb ice is starting to build. The heat sink effect of the motor temperature on the carb body has this sensor showing 22 - 24 degrees Celcius under normal conditions. Given carb ice forming this temp reading will gradually fall and if it reads 18 degrees C or lower I can expect to experience the effects of carb icing. At this point it will take approx 5 min of carb heat to restore temps to normal. The temps given here will vary considerably with each particular aircraft and are given here as a guide only. Hope this helps! Evan Gardiner, MCR 01 ULC Subject: RotaxEngines-List: Carb Heat with 912ULS RotaxEngines-List message posted by: Jeffrey A Beachy I have a Rotax 912ULS with the Rotax airbox. My cold air is supplied via a NACA inlet on the cowl then through a filter and on to the airbox. Carb heat is via a flap in the airbox which pulls unfiltered air from a muffler cowl to the airbox. I understand that the 912 series is not prone to icing, but I cannot find anything in the Rotax literature offering suggested use of carb heat. So, experts, when do I use carb heat with my 912ULS? Only if engine is running rough and icing is suspected? In landing patterns like a Cub? All those using the Rotax airbox with a 912, I would appreciate your experience and suggestions. Thanks! Jeff Beachy Zenith CH701 -- ________________________________ Message 7 _____________________________________ Time: 07:16:29 PM PST US From: "Dave" Subject: RE: RotaxEngines-List: Re: Throttle Cables sticking Keep the cables as short as possible too, just long enough to make smooth a radius if they have to change direction in your installation. -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Roger Lee Sent: Tuesday, January 29, 2008 11:14 AM Subject: RotaxEngines-List: Re: Throttle Cables sticking Here are a couple of things to do. 1. Use cable housing that has the plastic lining in it and not just plain steel lining. It allows the cable to move within the sheath smoothly and doesn't rust or develop rough spots. 2. Do like Jack said and remove the cable and use some cable lube 3. Step down a cable size to allow more room in the cable housing to move and not bind. On many planes trying to use 1/16" cable size is too big depending on the routing and turns that are made with the throttle cable. My cable in my CT is only 3/64" or 1.2mm. This is because it goes around a 1 1/4" size pulley and needs to be able to make the bend and be very flexible. Using the smaller size cable will allow your carb springs to work better and do their job. Use 7x7 or 7x19 cable. 7x19 is a little more flexible than 7x7. 4. Lube the throttle quadrant if you have one and make sure it moves freely. If it were me I would do all the above and then the throttle should be very smooth in its operation. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=161109#161109 ------------------------------------------------------------------------------------- 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.