So i learned a valuable lesson today..I'm a nut for having gobs of power on demand however i think i over did it today ... So i have a 60 size sig hog low wing sport plane that had a old enya .91 on it..the engine was old and ragged out and i wasnt impressed with the power, so i decided to get a power house of an engine...a super tigre 2300 a 3.7hp engine 1.410 cubic inches.... and about killed my airplane, i taxied out and 1/4 throttle and the plane floated up into the air like a home sick angel so i pushed the throttle a little more, the plane bolted..it had to be crusing at 80-90+mph. The power felt good to me so i decided to go past half throttle i eased to full throttle..i kid you not, that plane Bolted at 90+mph........ and then i heard that dreaded sound no r/c fly boy wants to hear..the BURRRRRRRRRRRRRRR of Flutter!!! The flutter was so loud and sounded so violent that other flyers forgot about there airplane and yelled the dreaded " FLUTTER!!!! " i was sure the plane was going to explode any moment...so i quickly, instantly throttled down to a crawl and checked the planes wing and rudder in a high, slow fly by and finished trimming it out before i landed it..i rolled out to the left and lined up my plane for the grassy runway..a slight cross wing pushed the plane a little, I cut the throttle to idle and this plane glided in so well and so flat even with the 35oz engine on it, landed it safetly.. I gave it the after flutter check and found the plane to be in great shape.. no damage!! I was suprised...i was sure the monokoat somewhere on the plane had tore off but it was not damaged nothing internal was damaged, and the rudder and elevator was AOK!! thank you who ever was watching out for me! I learned that made a super tigre 91 would have been a wiser choice but..sometimes you gotta push the limits til the limits push back! =)