Got a problem with my UCD46.
Running an OS Surpass 91 FS with a 15x4W prop
Pretty well balanced out however i am starting to move the battery back to get the CG more aft.
Problem is in level flight i require about 3 degree up elavator to maintain altitude, this is at quarter to half throttle so it is not sinking. Thought it was down thrust that was needed, added a few washers behind the engine but this did not do anything.

Any thoughts, great plane but clueless at the mo.