I ran into the same problem with the .91. I just used a countersink head screw for that one. Since you can't use lock washers, you should make sure you use LockTite on the monting bolts, though.

First flight with mine today. first thought was, "Man, this thing flies sloooow". Second thought was, "Man, this Saito has a BUNCH of power!" Third thought - "Man, this is gonna be a LOT of fun!" I never got it over about half throttle. Didn't need to. Hovers were around 1/3 or so. I suck at hovering, but I was able to take my hand off the right stick and hover it for 5 seconds or so.

One thing I realized, though, is that with the Saito .91, that 8oz tank isn't going to be quite enough. Has anyone else tried a larger tank, and if so, which one fit the best?