I didn't think so. Do i need to try to explain it better?
It may not be the problem but it just sounds like there is not voltage and current to fully retract the solenoid. This a common problem JD had with the solenoid shift starters on their equipment due the long runs of wire in the trigger circuit. Since JD primarily only used Kawasaki and Kohler engines, those are only ones that I have seen the problem on but it is possible with any engine with a solenoid shift starter. JD actually sells a kit for this but it is easily by the tech once they understand what JD does with the kit at a much lower price.
Wire does have resistance as low as it is, it still becomes a problem on long runs; unless, a larger size is used. This is especially true at the currents involved.
Now the disc the fellows are talking about only affects the main starter motor and has nothing to with the solenoid retracting; unless, it get welded to the contacts then the starter motor would constant spin. Yes I have seen them burned that why they use copper as it doesn't welds easily especially to it self. I have seen a few remote solenoids contacts to be welded from excessive current and the starter operated basically the same as the remote solenoids except it also engages the starter bendix.