Yes... I do... I did exactly 304 flights on the mufflers before I noticed the rattling. I continued to fly until I changed over to the 200 and that was when I also changed from the 1090's.
Thank you. That is a pretty good number of flights, seems to work out at the pair of pipes costing about $1-$1.50 / flight ... I'd prefer they didn't break... but for the additional power they sound like a good option. In your opinion, is it the case that the Planebender smooth pipe is a more solid product? They're pretty expensive to get to Europe but if they did twice the number of flights it would make economic sense!
I didn't have to but I did at one point since I had them out anyway on an air frame change. I used a grill cleaner/degreaser that was discussed in a thread about this a few years ago. I think maybe Clorox made it. At any rate, it's not sold anymore. Cleaning them didn't produce any change and the tune stayed the same. I would think if your pipes were clogged/clogging you would see a need to re-tune and, barring any other changes, that would be a red flag. I haven't needed to touch the needles on my DA170 in years and many, many gallons of gas and in all that time I've had a total of 2 dead sticks. Both were pilot error (forgot to fuel up between flights. Duh).
Not sure if it's relevant but 14" is best for RE3s. You give up a tiny bit of power but have better transition (less peaky). I originally had my pipes on a DA150 with 11" headers. Very powerful but the pipes came on like a rocket booster.