I have just put my Great Planes Big Stik (.40 size) on the CG stand, it is modified to be a tail-dragger and has a heavy Rossi R45 motor to pull is along. I have the battery and radio as far back as possible (just in front of the servo mount) and am still finding myself about 1"+ too forward of the recommended CG (3-3/4" from leading edge). Way nose heavy. The engine is mounted with the recommended distance of firewall to prop thrust washer of 4-3/4". I could move the engine back about 1/2" which should improve CG matters a fair bit before adding ballast. Is there something magical about the 4-3/4" spacing to the thrust-washer or would this engine move be ok?
Obviously if I have to add lead weight ballast is it common to cut a hatch in the tail somewhere to install, any better ideas on getting lead back there? As it stands now (without the engine move) I need 3 oz of lead on the elevator to make it balence! So, some ballast will be needed even with the engine moved back somewhat.