I'd double check that left thrust. I also would take everything I see in a Phoenix ARF manual with a grain of salt. I bought their 40 size Yak-54 last week and as I have been working on it, I'm really starting to regret it.

The instructions are pretty sad. This isn't a big deal since I've built numerous kits and assembled many ARF's so I can figure things out as I go. Still, based on the vagueness and poor wording, I don't trust anything the manual tells me as far as CG and other specifications. I will double check EVERYTHING myself.

The motor mount included with the plane is a joke. It's too narrow to fit even a 2-stroke .46 and appears to be made of some sort of rubbery plastic; way too flexible for the job. I knocked out the blind nuts, filled the holes with hardwood dowels then re-drilled the firewall to use a GP adjustable mount.

The fuel tank stopper with plastic tubes is also pathetic and will get replaced.

The cowl is formed nicely and painted well but the diameter is too large for the fuselage. Once the cowl is screwed down, it will likely bulge in places. Maybe I'll try cutting a section out to make it fit better. There is also nothing but balsa sheet to screw the cowl to from what I can see. I'll have to add some hardwood to back up the screws.

The included pushrods are very tiny in diameter and will likely flex. I'll have to replace them with 2-56 rod or maybe some ny-rods.

One positive thing on the plane though is the covering. It is as close to flawless as I have ever seen on an ARF. I only needed to iron the seems as a precaution and it has stayed pretty much wrinkle free in my warm garage. Otherwise, I am not too thrilled. Hopefully it will still be a fun little plane when I am done.

On your Decathalon, I agree with combatpigg, really look at the CG and possibly move it forward some then make sure it is trimmed right.