Thanks to everyone for all your insight and "hand holding" so far.

I will swap out the prop for a 11x6 or 12x6. I thought the manual suggested a 10x6 for run-in (it’s a brand new engine), but it may have just been that’s what I had available when I started putting it together.

Jhetmech05: Fuel tank is empty. I used an epoxy mixing stick to secure the fuel tank but even that was in the instructions. I will double check to make sure I didn’t leave my cordless drill or something in there!!

broke_n_bummin: The manual says the CG is 4 1/8" back from LE, and that it can be moved forward or aft 1/8" from the 4 1/8" mark, but that initially it should be flown w/ CG @ 4 1/8" back from LE. So yes, there is 1/4" of play.

Da Rock: I will need a flat battery pack to put underneath or behind the TE as there isn't enough clearance for my 2x2. I will follow your suggestions of checking the CG w/o the battery before proceeding or purchasing a new battery. If I do build a battery box do I build to fit a battery wrapped in foam or a bare battery? How do I secure the battery in said box? (I think this is going to be the answer to my problem, thanks for your help)

On a side note, I have built several combat planes (gutter pipe and coroplast) and have found balancing rather straight forward. I get them flight ready before determining where to place the wings for proper balance. This is my first experience of moving the “guts” around to achieve proper CG. The other way is easier!