ORIGINAL: raydar
The magnum 70 weighs almost the same as the sc 90 fs I have i think thats why im thinking the 91 fs would not be a issue to fit
not sure why my font is bold now im not shouting
thanks for the quick replys so far
dont make this mistake, i bought a yak54 and it called for a 46 2 stroke or 70 4 stroke. i used the same line of thinking you just used...well its only 3 oz more... but that isnt counting the much larger prop and the larger spinner (you should use an aluminum one for 4 strokes)
get the 70 and you will be fine, my yak flew horrible even though the balance was spot on, just to much wing loading and not enough speed w/ the 4 stroke. it may work if this is a really floaty plane but i still wouldnt do it
the 70 will be plenty of power, the 61 may be enough.