---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Thu 01/31/08: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:37 AM - Re: Re: Carb Heat with 912ULS (Duncan & Ami McFadyean) 2. 03:49 AM - Re: Throttle Cables sticking (Duncan & Ami McFadyean) 3. 05:16 PM - Re: Re: Carb Heat with 912ULS (Evan Gardiner) 4. 09:31 PM - Replace Needle? (Guy Buchanan) 5. 11:51 PM - Re: Re: Carb Heat with 912ULS (Robert C Harrison) ________________________________ Message 1 _____________________________________ Time: 03:37:26 AM PST US From: "Duncan & Ami McFadyean" Subject: Re: RotaxEngines-List: Re: Carb Heat with 912ULS With some makes of digital thermometer it is possible to buy additional probes. I have these (3 in total) wired through a selector switch. Problem then is that the switch has its own resistance and reduces the reading by (in my case) 6 deg; but at least this reduction is consistent. I don't generally see carb body temps less than 20C (Europa Classic, cold air supply to carbs., no formal carb heat), unless OAT is well below freezing, whilst under-cowl temps in the proximity of the carbs are about 10C greater than this. Elsewhere (Skydrive?) it has been mentioned that a carb body temp of anything less than 2C is cause for worry; so not sure who is right on the issue of limiting temperatures, and not willing to find out! Duncan McF. ----- Original Message ----- From: "Gtblu" Sent: Thursday, January 31, 2008 2:26 AM Subject: RotaxEngines-List: Re: Carb Heat with 912ULS > > Good one. I've got some in the hangar. Did you put another probe onto the > thermometer or did it already have two "externals". I f so what breed are > they.. I have only seen indoor/outdoor with one internal probe and one > extended external. > > -------- > Slepcev Storch > 912 uls 731 hours > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=161465#161465 > > > ________________________________ Message 2 _____________________________________ Time: 03:49:51 AM PST US From: "Duncan & Ami McFadyean" Subject: Re: RotaxEngines-List: Throttle Cables sticking I did something similar, but had the two Bowden cables connected directly to the vernier via a slider arrangement. This worked OK with two fuel injection throttle bodies, which are extremely difficult to balance accurately (far more difficult than carbs, even without a balance tube). For the ROtax, I have teflon lined stainless Bowden cable which works OK, and at reduced tension on carb springs. Has to be stainless with teflon, for best effect. And same length of cable for each carb, irrespective of actual requirement. For nylon/acetyl lined cables, the possibility of the liner softening and welding the throttle open on a long cruise (if the cable is routed near to under-cowl hotspots such as exhausts) needs to be considered. Duncan McF. ----- Original Message ----- From: "Steve Hagar" Sent: Thursday, January 31, 2008 1:59 AM Subject: RE: RotaxEngines-List: Throttle Cables sticking > > > I have installed a Cessna Push pull vernier type throttle single cable up > into the engine compartment. Once there, it is split into two where the > normal motorcycle type cable that comes with the plane is used. Each > length of these is 18 inches or less long and is easily overcome by the > carberator springs. > > Steve Hagar > A143 > Mesa, AZ > > >> [Original Message] >> From: Rich & Sandy Schultz >> To: >> Date: 1/28/2008 10:49:46 PM >> Subject: RotaxEngines-List: Throttle Cables sticking >> > >> >> >> 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 3 _____________________________________ Time: 05:16:15 PM PST US From: "Evan Gardiner" Subject: Re: RotaxEngines-List: Re: Carb Heat with 912ULS Your point is very valid, it is not so important what the actual normal tempereture reading of your carb body is - what the temp guage gives you is the ability to recognise that the carb body has, over a short period of time, cooled by 4-6 degrees. Under these circumstances the only thing that could have caused the carb body to cool that much, that quickly, must be that a build up of ice has formed on the carb throat. Time to deal to the problem! Evan Gardiner MCR 01 ULC > > > With some makes of digital thermometer it is possible to buy additional > probes. > I have these (3 in total) wired through a selector switch. Problem then is > that the switch has its own resistance and reduces the reading by (in my > case) 6 deg; but at least this reduction is consistent. > > I don't generally see carb body temps less than 20C (Europa Classic, cold > air supply to carbs., no formal carb heat), unless OAT is well below > freezing, whilst under-cowl temps in the proximity of the carbs are about > 10C greater than this. > > Elsewhere (Skydrive?) it has been mentioned that a carb body temp of > anything less than 2C is cause for worry; so not sure who is right on the > issue of limiting temperatures, and not willing to find out! > > Duncan McF. -- ________________________________ Message 4 _____________________________________ Time: 09:31:44 PM PST US From: Guy Buchanan Subject: RotaxEngines-List: Replace Needle? All 582 drivers, past and present, I'm doing my 150 hour check and the book says I should change the needles and needle jets. Should I? Or does this date back to the days before the needle O-rings? Do these wear out from vibration? Anything else I should change out at 150 hours? Thanks, Guy Buchanan San Diego, CA K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar. ________________________________ Message 5 _____________________________________ Time: 11:51:26 PM PST US From: "Robert C Harrison" Subject: RE: RotaxEngines-List: Re: Carb Heat with 912ULS Hi! All I have been passed a Rotax CD which seems to recommend some form of carb heat when a 914 is fitted with an intercooler (yes, you've guessed it I have such a combination!) Whilst I do appreciate that the presence of moisture and ambient humidity provide a huge range of Carb icing probabilities I had understood that on a straight turbo combination the final intake temps are in the 40deg to 60 deg. Fitting the intercooler does drop the intake temps to approx 16 deg at 10,000ft with ground ambient 4 deg (all celcius)and the inside of the screen freezing over! With the air filter directly turbo intake mounted it will be a humongous task to re-route hot air to the system. ST Aviation have a metal carb heat electric element (obviously two needed on the Rotax which "pull" 10 amps when switched on )has anyone tried these guismos on a Rotax? Alternatively does anyone have suggestions concerning collection of engine compartment air to provide carb heat in an icing emergency? Regards (here we go again!) Bob Harrison G-PTAG -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Evan Gardiner Sent: 01 February 2008 01:12 Subject: Re: RotaxEngines-List: Re: Carb Heat with 912ULS Your point is very valid, it is not so important what the actual normal tempereture reading of your carb body is - what the temp guage gives you is the ability to recognise that the carb body has, over a short period of time, cooled by 4-6 degrees. Under these circumstances the only thing that could have caused the carb body to cool that much, that quickly, must be that a build up of ice has formed on the carb throat. Time to deal to the problem! Evan Gardiner MCR 01 ULC > > > With some makes of digital thermometer it is possible to buy additional > probes. > I have these (3 in total) wired through a selector switch. Problem then is > that the switch has its own resistance and reduces the reading by (in my > case) 6 deg; but at least this reduction is consistent. > > I don't generally see carb body temps less than 20C (Europa Classic, cold > air supply to carbs., no formal carb heat), unless OAT is well below > freezing, whilst under-cowl temps in the proximity of the carbs are about > 10C greater than this. > > Elsewhere (Skydrive?) it has been mentioned that a carb body temp of > anything less than 2C is cause for worry; so not sure who is right on the > issue of limiting temperatures, and not willing to find out! > > Duncan McF. -- -- 27/01/2008 18:39 ------------------------------------------------------------------------------------- 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.