You are probably right on the CG. I believe mine to be a bit nose heavy but I am used to how it flies so havent messed with it. Come to think of it, one of the stick-on weights near the tail is missing...
ORIGINAL: 8178
I fly one of the Monokote versions with an Irvine 53 and it flies fine. I’m using a 12 ounce RST tank. It moves along briskly and will land slowly if you have the CG setup correctly. I had to add some weight to the tail to get the CG set because of the size and weight of the 53. I also have a kit completed but have not flown it yet. The Monokote ones are similar in design to the kit but the new red ones are different in shape and use some other type of covering.