You may have a CG problem locating that servo in the tail. Remember, every extra ounce in the tail wil need 8-10 ounces in the nose just to maintain CG. I built 2 H 9 Mustangs with identical equipment, when the second plane was finished, the CG check was so far back it needed 1.5 lbs. hung from the engine's crankshaft behind the spinner to get the CG where it should be. Since that was not possible, it would have taken a lot more weight bolted to the firewall. It took a lot of work and some serious weight transfer to get the GC right. And I could not find any obvious reason for the tail to be that much heavier. The horizontal stabs from the previous plane were a few grams lighter so I used them after repairing them. I substituted lighter carbon rods for the steel hinge rods to save 1.5 oz.and moved the servos from the stabs to the fuel tank area. To avoid adding elevator control rod weight I used the last of my supply of Sullivan Carbon ny-rods (no longer in production). Then I had to leave off the Tail gear doors. It finally balanced in the middle of the recommended CG with out any nose weight, except for 2 large, heavy NiCad rec. batteries at the firewall. It was worth the extra effort- this plane flies better than any other Mustang I have had my hands on.