On the same day I flew my u can do 46 with a gms 61, and the engine quit after i landed , the next day i took it apart and the os #8 plug was destroyed. but the saito plug was fine. I looked at it and adjusted the valves and set the low needle to factory settings and it fired up with no problems what was the problem I do not know, but I broke one rubber mount , I ordered two new sets that my niece is bringing here on the 10th of July. my friend videoed the flight with a cell phone as soon as I get it I will post it. her are some pics of damage and repair.