Hello, I hope this finds you well! Thank you for any help, as it seems to be stumping most people. I have a brand new 914UL on a SeaRey, which is now just over 100hrs.

Around 80hrs I started getting a rough mag check check on the R mag @ 4000rpm. I'd let it sit at 4000rpm for around a minute and it'd seem to clear up. At the 100hr oil change I decided to swap the plugs. I'm using the "newer" style rotax double prong plugs. When I pulled the plugs, cylinders 1 and 2 are velvety dark, while cylinders 3 and 4 look like they are tuned correctly.

It seems like messing with mixture would not be helpful, as cylinders 1 and 3 are on the same carb, but acting differently. Is this just an artifact of a SeaRey being a pusher? Or is there some way to tune the such that the plugs are all burning evenly? Any thoughts on things to check? I've included a picture (annotated with my weird plug layout) to show the issue. The plugs in the photo were pulled after a flight around 100hrs on the tach.

Thanks again for any thoughts and help!

9179_1_914plugs.jpg (You do not have access to download this file.)
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