Sorry about lack of specific model details, forgot to write them down. Pictures/descriptions of the Model LC121P look very similar to this mower.
My sister in law called and wanted me to look at her push mower. Got it last year at the local Sears Hometown store. Briggs and Stratton engine, I think the metal cap said OHV with the spark plug slightly offset, guessing 20-21" deck. Pulled the starter rope and would only pull a little bit. Pulled the plug and still the same issue. Turned the mower on its side and turned the blade, maybe a 1/4 turn in each direction before stopping against something. Gave the blade a little more of a "omph" when hitting the stop and we heard a clunk and the blade now turns freely. Sat the mower back upright and now the rope pulls freely, too freely. Pulled the plug again and had her pull the rope and felt nothing at the spark plug hole and nothing at the exhaust with the spark plug back in. Asked if it ran last year before they put it away and my nephew finally admitted as he was finishing up with the last mow of the season (in high grass) it just "died" and he put it away.
Sooo... lack of compression. Ideas on what may have happened? Being an end of season purchase last year it may still be under warranty but she moved a few months ago and doubts if she has the paperwork. Why they didn't take it in when it quit last fall? I have no answer for that question.
I forgot to mention the blade did turn when she pulled the rope. Loooong day, just got done roofing when she called and had to deal with this and was pretty much "wiped out" when I typed the post.
#2 with the broken rocker sound like a strong possibility.
Not going to take anything apart until she checks out the warranty. Then check under the OHV cover if the warranty is expired.
