I have a troy bilt with a 18.5hp motor. It turns over, has spark but I don't think the piston is moving. I put a stick in the spark plug hole and turned the motor over and the stick did not ever move. I got this from a guy who took it in and the repair shop said the parts where going to be $225 and $240 in labor. What could this be?

Hi,
Broken connecting rod. Estimate sounds low to me on the advisable parts and about right for the labor.
Peace,
Clarke