Incorrect nut
I missed to select throttle linkage nut. I used shock piston nut. It is 2.2 mm diameter. Corrected size is 2mm. Finally it never loose throttle screw. And I change to set switch post inside little. For avoiding brake switch on clash. Rear stefner mount modify is completed. Probably rear bulkhead screw hole will be foolish. I can't get bulkhead yet on A main.