I have a PC200LC-6 ser#A80880 with the S6d engine if I remember correctly. My throttle controller is pulling the rack back but not shutting off the engine. Does this controller work like a solenoid with a pull back wire and a separate hold wire? Once the ignition switch is shut off, I hear the controller pull back several times but usually not long enough to kill the engine. Once the cycle is started, I can hear the controller motor cycling the pull back at least 4-5 times before the main power switch is disconnected. Any diagnosis information would be appreciated. I'm pretty sure this will be a wiring issue unless the controller motor has gone out.
Before you do anything else, make sure the throttle ball joints and all the linkage points are tight. If either end is loose you will need to replace it. That is about ninety percent of all the throttle issues I've had with those machines. Here is the book procedure.
Thanks for the help. All of the linkage is tight without any slop. I've also lubed the spring rod to make sure it pulls smoothly. The electric motor pulls the linkage back to the stop position and then lets go. This happens numerous times and cycles the same. Eventually, the main switch cuts power and the engine continues to idle or sometimes it does kill the engine. This has been doing this randomly and not exactly having this problem every time I turn the ignition switch to off. Sometimes it turns off on the first attempt as it should. I'm still not sure if it's in the wiring or something else. I did have the throttle controller apart recently to make sure everything was fine in the internals and give it a good inspection/cleaning/lube. I had a problem with it several years back and it turned out to be a small bearing that locked up the mechanism. I replaced the bearing and it's been fairly trouble free since, other than the idle speed was lower than it should have been. I've got the idle back up about where it should be. Maybe I can try re-adjusting the linkage as in the directions and maybe this will get me working again. If not, then I'm pretty sure it will be in the wiring.
Next thing to do then is turn the key on, put it in H mode, turn the auto decel off and turn the dial all the way to high. The linkage should just be touching the high idle stop. Adjust accordingly.