Also you could do a little test by adding a slight shim under the back edge of the wing.. It might fly a bit better, maybe an 1/8th of an inch or so. Its probably a bit tail heavy as mentioned.. However all of us that have built any flying object HOMEBREW... know that sometimes it takes some tweaking.. Be glad you still have something to tweak ! I have had a few experiments go wrong on the first flight ! hahahahahaha