ORIGINAL: whstlngdeath
That doesn't sound right. 9 oz. is a bit much to add to a .40 size plane. The instructions does say 6 - 8 cm from the leading edge at the wingtips. Sounds pretty confusing, especially if the wingtips are rounded. Still, 9 oz. sounds like too much.
Jesse
I have test flown the Seagull Zero ARF with the cg per the instruction books recommendations. I called Horizon Hobbies to clarify the CG stitauion and they said the 6-8 cm was from the LEADING EDGE OF THE OUTERMOST RIB. I marked those positions and stretched a string from each wing tip cg position and made my cg marks on the fuselage. When we balanced the Zero it took about 12-13 oz attached to the motor mount to balance about the mid-range position of the recommended range. The all-up weight without fuel was 6 3/4 lbs and she flew very well, so I don't think that the 9 oz is too much for this aircraft if she balances in the prescribed range and the overall weight is satisfactory for a .40.
I hope this input helps
and good luck to you. Let us know how things go in the test flight.
PS - You might want to check out my posting in this thread on this bird.
Howard D. Keney - hdkeney