---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Tue 04/26/16: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:43 AM - Re: Securing Muffler Springs (Watkinsdw) 2. 02:05 PM - Re: Securing Muffler Springs (Gary Aman) ________________________________ Message 1 _____________________________________ Time: 05:43:41 AM PST US Subject: Kolb-List: Re: Securing Muffler Springs From: "Watkinsdw" I, too switched to SS springs on my 912 ULS with its Titan exhaust. Stainless Steel springs cured the problem of periodic breakage, although I only flew it about 50 hours after the installation before it was sold. It was always a pain when doing pre-flight and noticing that I needed to replace a spring, assuming I missed it on the post-flight inspection. Here's another twist- at one point, I noticed that the tangs on the exhaust system that the springs hooked to showed considerable wear from the vibration, and I had two of them tig welded to build them up as soon as I noticed it. It's worth checking, because that would be another way to lose a spring and the safety wire connection as well. If you use high temp goop on both ends of the spring where it connects to the tang, any wear could go unnoticed. Dave Watkins Pompano Beach, Fl Read this topic online here: http://forums.matronics.com/viewtopic.php?p=455477#455477 ________________________________ Message 2 _____________________________________ Time: 02:05:40 PM PST US Subject: Re: Kolb-List: Securing Muffler Springs From: Gary Aman stainless steel springs give an added margin of saftey.From JBM. > On Apr 25, 2016, at 2:38 PM, KIRBY, DENNIS T GS-13 USAF AFMC AFNWC/EZS wrote: > > > Kolb Friends - > > I'm sharing with you a tip that may prevent you some grief that I encountered recently on my Mark-3. One of my muffler springs broke on a recent flight and departed the engine. Went thru my Powerfin prop and it took a bite-sized chunk out of the leading edge of one prop blade. Damage was beyond repair - cost of a new blade was $250. > > All 8 springs on my Rotax-912 muffler are safety-wired, per common practice intended at securing the spring when (not if) they break. I always check the safety wire on each muffler spring as part of my preflight. Apparently on this day, one of these safety wires was worn partially through and still appeared secure when I checked it. When the spring broke in flight, the instantaneous energy must have been sufficient to break the already-weakened safety wire, resulting in the spring's departure from the engine. Double failure. > > So, here's the tip: I will no longer rely on ordinary safety wire to secure my Rotax muffler springs. I've upgraded to 1/16" braided cable to secure these springs. This is bicycle brake cable, available at any bike shop. I use one piece (about 10 inches long) for each pair of springs. The cable ends are joined and secured using a swaged ferrule. Cheap, easy to install, and most of all, WAY more secure than a single strand of .032 safety wire! Constant engine vibration will not wear thru it, as it does on safety wire. > > Fly safely ... > > Dennis Kirby > Mark-3 / 912ul > Sandia Park, NM > > > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-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/kolb-list Browse Digests http://www.matronics.com/digest/kolb-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.