ORIGINAL: foresterxt
I had a magnum 52 four stroke on my 4*40 last summer (first summer flying

) and it flew fine, albeit a little slow. I ended up pretty much flying full throttle the whole time doing low flybyes with a grin on my face. I've since decided to up the engine size so I put a Thunder Tiger .65 (GP61) 2-stroke that I had laying around [>:]....Ought to be a blast.
Yeah I think you will see a slight difference in performance. I wouldnt fly it full throttle all the time like you did with the magnum 52.... that would be interesting