Lawn Tractor Engine

Complete engine - Electric start - actually runs good....Small vibration when idling - Reason being only one piston is moving ....the other is not.....still starts and runs good...I'm guessing broken connecting rod or something along those lines... standard 1" thick x 3 5/32" long vertical crank....Removed from a Craftsman LTX1000...asking $100 or Best Offer