Only 800 hours since the last replacement, I had to again replace the 16" length of flex exhaust tubing . This is not as easy as it sounds, as I had to loosen the hose clamps that secure the muffler to the belly tabs and then loosen the automotive muffler clamp on the upper end. This took almost a minute, and to make things worse I then had to make a special trip to the local Car Quest store where my buds there extorted almost 8 bucks out of me for a replacement length. Once back in the hangar (where it hasn't gotten over 70 yet due to it's earth sheltered design, so conducive to extended maintenance during heat waves) it was another bout of wrenching to re-install the new flex, and yet another minute or so gone forever. The worst of it is I pretty much know that no doubt in another 800 hrs or so I'll have to go through it all again, another 8 bucks and minutes of my time.
Then it got worse, I noticed that the tubing stub the flex engages (no clamp there, it must be free to move a bit) that is welded to the muffler body is showing signs of wear after only a total time of less then 1200 hrs. It's clear that by the time I reach TBO on the Rotax (2000 hrs) I'll probably need to weld a new stub on the body, another 20 bucks down the drain, and only for a couple thousand hours of flying worth of wear.

Yeah I'm kidding, since I discovered the key to extended life of the flex is to only clamp ONE end, I have gotten great wear out of it. Before, with both ends clamped, it'd last less then 100 hrs. The whole concept has been incredibly trouble free for me, thank you to the late and great Tony Bingeles for writing about it years ago! Just the other day I taxied past an open door to a buddies hangar, and parked about 30' away. When I walked in he was on the phone and looked surprised to see me, as HE DIDN"T HEAR ME TAXI BY.....
