control box locked up at full speed at least it was on the hose and I was just primn

[fishjumped]

fortunatly I did not turn the key to start it the handle is stuck WOT what may have happened it shifter great the day before I am breaking in a Rebuild motor 260 mercruise this is a 1984 control box is there help available to understand this problem also the sqquare throttle only button was falling off but I pushed it back on a couple of times is there a screw that may have jammed the tandle in full throttle and not let it back to 3/4 let alone N pleas erespond thank you