DT100 partially locked up

[Zodiak]

90's DT100 was bogging out (total loss of RPM's unless in Neutral), so we sprayed some Sea Foam in the carb and then the motor sputtered and died. When we started it back up the starter locked with the bendix on the fly wheel. We moved the flywheel and the bendix popped back down but now the fly wheel can only be turned 1/3 rotation forward and back. We checked if in Forward and Reverse and the prop still turns and free spins in Neutral but you cant get the flywheel to make a full rotation. Were thinking from the manual that by opening exhaust covers on side of cylinders that we might be able to see the problem if it something busted causing piston the not allow a full rotation. Any thoughts fella's?

[Zodiak]

Update

We pulled one of the heads and it looks like a whole lot of chunks of possible piston or something else ground up inside the cylinder.

[JUST-IN-TIME]

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