Chainsaw Repair

IIRC the MS 200 has roller main bearings? So the following scenario would not happen with roller bearings on the MS200.

If the cage is worn out on one of the crank ball bearings, all the balls will get on one side and lock the crank up. You can jiggle the crank a little and the balls will distribute around the bearing for a short while.

There could be something loose inside the engine and it is catching in the exhaust port? Pull the muffler and look into the exhaust port?