briggs and Stratton 14.5 locking up when starting, model287707?

I got this from my sister after my brother in law passed away. It had set for several years. Turned over very hard but got it started. Carb needle valve was stuck and filled oil with gas and smoked like crazy. Fixed that, now it tries to turn over but locks up during the stroke. Took the plug out it turns over fine. Replaced battery, starter and solenoid, still same thing. Tried putting some oil in cylinder wall, did not work.It is a B&S model287707, Type 1224-E1, code 97100620.Could it be a bent rod and if so how do I check it? Thanks so much for your help.