I dunno....I just put a Saito 1.00 on a Sig 4 Star 60 and even after adjusting it and getting it as smooth as possible on the bench, it vibrates like crazy on the airframe.

So...I would if I were you. I don't know that it can hurt anything, other than your pocketbook. I can't rememeber what they cost last time I saw them...$30 or $40???

The next plane I build with a 4 stroke over a .90 will have soft mounts.