I replaced the top 2 exhaust seals between the titanium exhaust pipe segments, one on each side. The exhaust pipe on the right side serves 5 cylinders, the left side 4. The old carbon steel clamps, crush sleeves and shims were in pretty rough and rusty shape. Carbon Monoxide readings appeared to be lower after the change, so I ordered the other 4 clamp/seal sets. I installed these today.
I competed in the 2017 Apple Cup Aerobatic Competition at Ephrata WA last week end, and got Last Place
I got turned around on the first two flights and Hard Zeroed all of the maneuvers after the errors. Enough to win the (new for this contest) Hard Zero award! For those of you who have competed in IAC contests, you will understand that a change in the "Contest Wind" from what you are accustomed, can be a real hazard. As a newbie who only experienced wind from the South at this airport, I "flew" right into a disaster when I over rotated a 1-1/4 turn spin, then flew "out" to fix it. Good plan, but All Maneuvers after that were flown to the "Wrong Wind".
I still had a blast, and Judge Dave Watson was kind enough to score all my HZ's in the comment section to let me know my flying was actually good! I did much better on the third flight, so I'll take that as a lesson and move on...
I'm getting a lot of vibration from the stock V530 propeller, which I reduced with a piece of tape on one blade. Now I have access to a Dyna Vibe balancer set up on a frame I fabricated to the gear case. Next 'days off' I will run it to balance the prop and check calibration on the VDO tachometer.
Over-All, I am Very Impressed with "Honey Badger" my Yak-55M.
Perhaps you've seen the Youtube video https://www.youtube.com/watch?v=M0wi7Ugct1w
or the more 'risqué' version narrated by Randall.
So I call my Yak55 "Honey Badger" because it doesn't give a Sh** what I do to it in flight. It just keeps going and makes me look good!
IAC aerobatics is a very 'Mental Game', much more than flying good aerobatic maneuvers. It's all about remembering what you are supposed to be flying, monitoring where you are in the 'Box' observing your progress and making corrections going forward.
I've been trying Zep Big Orange in a spray bottle to wipe the oil mist off the airframe with paper rags, but I got some Lemon Pledge for the canopy, and it turns out to be a very effective bug and oil/dirt remover! Over on the Vansairforce forum, Lemon Pledge seems to score well when compared against Plexus so, at a fraction of the cost I gave it a try. Little did I know it would be so handy on the airframe.