Small Engines (Lawn Mowers, etc.): Lawnboy quit, gold series, 8oz

Question
I have a lawnboy gold series commercial grade   5hp mower. It suddenly stopped running, nothing was hit. I pulled the spark plug out. You can't turn the engine by pulling the string, but you can by pushing on the blade. It is very hard to move. I use lawnboy oil, 8oz to 2 gal of gas.
The piston does move inside the cylinder.
Can you help?

Thanks Jim

Answer
Hi Jim,

Make sure that the recoil is not binding.  Remove it if needed.  Then, if the engine turns hard with the blade, I would suspect internal damage.  Maybe a seized bearing.  You will need to disassemble the engine.

Let me know how you make out.
Michael