I have one of those! Ok, list my set up.
Box stock OS LA 25
Venturi .240"
OS spraybar
factory muffler with the stinger filed off hole size .270"
APC 9-4 Sport prop
3oz uniflow tank
10% nitro 10% castor 10% klotz
one #4 flat washer under each front motor mount lug for out thrust
Balance point 1-3/4" behind leading edge
Tether point 3" behind leading edge
Rudder offset 11/16"
Lines are .015" x 60' handle to thrust line.
I run the engine flat rich in a 4 stroke for a 5.0 lap time.
Hope that helps
Motorman