ORIGINAL: da Rock
Now go to the throttle arm on the carb. Unhook it and move the arm until the opening in the intake is half opened. Will the throttle arm and the pushrod now make a 90 degree angle? If it does, adjust the length of the pushrod to connect to the arm where they will have that 90degree angle.
If it does not, then loosen the screw holding the throttle arm and move that arm to the 90degree position. Tighten the arm and adjust the pushrod.
You now have the rigging setup so the servo will rotate the throttle equally in either direction.
Now........
Wow, talk about fast responses! [X(] Thanks.
OK, with the throttle stick at middle position, the servo arm is at center, the servo arm and pushrod are at 90 degrees, and the pushrod and throttle arm are at 90 degrees. The throttle barrel is half open. That's been the case all along. At full open throttle the barrel is fully open. At full closed throttle stick the barrel is open about 1/16tb inch. Just what the book calls for. The trim switch will NOT close the trottle and kill the engine. That's when folks started fiddling with the cut off switch, end points and sub trim. (still don't know what sub-trim really is).
Edit
Initially the throttle push rod was binding on the engine mount so I slightly adjusted the offset bends in the pushrod to give clearance. Everything is now free and clear.
I can loosen the set screw holding the pushrod in position at the servo arm and easily move the throttle barrel to fully closed with the pushrod, so the stop on the throttle arm doesn't seem to be the problem either. The servo is not binding at either full open or full closed.
So, I'm still at square one.