Ralph, you are right about the advance. Anything done wrong causes problems and I'm sure you have seen a lot of engines timed wrong by people who didn't have a clue. Timing an engine is not rocket science and there is plenty of information out there on how to do it. CH Electronics web site is a good reference. I don't find the throttle coupled spark advances on the Brison engines to be sloppy. The Delrin ring is a very nice fit and the ball joints allow no slop in the linkages.

Flip and Fly I'm sure the Brison 5.8 shakes a bit more than the ZDZ80RV. The 80 is one of the smoothest engines out there in its size class. As I said I use my 5.8 on a Ziroli Corsair which has a very strong frame and I don't notice any unusually high amplitude shaking. If you have ever put your hand on a running plane powered by a Brison 6.4 or a BME 110 Extreme twin, they shake too. I wouldn't be inclined to put a 5.8 in a 24# Edge 540. Any time you take a powerful engine and produce a strong power pulse each revolution you are going to get some shake. I wonder if the in-line twins that alternately fire produce less shake. By the way, what is your new project?

Happy Thanksgiving

Ken