RE: Any 4*40 owners with a 4 stroke?
I just installed a Saito .62 in my ARF Four Star and used the Dubro 4 stroke linkage (part # 655), 2 x Dubro ball links (part # 190) and a 1" length of 2-56 threaded rod.
See the picture for a mockup that i assembled off the model for clarity.
You might also need to drill 2 holes in the cowl cheeks for the needles, depending on the size of the motor.