Update.
I was finally able to repair the throttle mechanism, the problem was found in linkage play. First, the speed tube grooves pushed by the hand throttle were stretched. Second, the bellcrank and the swivel it rotated on were worn, allowing for more than rotary motion. Third, one of the holes in shaft #36 was stretched. I replaced the 3 mentioned parts as well as the foot pedal and its lever and adjusted the mechanism according to the procedure in the manual and it all seems to be working great. Thank you all for help.
I was finally able to repair the throttle mechanism, the problem was found in linkage play. First, the speed tube grooves pushed by the hand throttle were stretched. Second, the bellcrank and the swivel it rotated on were worn, allowing for more than rotary motion. Third, one of the holes in shaft #36 was stretched. I replaced the 3 mentioned parts as well as the foot pedal and its lever and adjusted the mechanism according to the procedure in the manual and it all seems to be working great. Thank you all for help.
