Hi theppy2760, welcome to Outdoorking.
I am concerned that you mowed 4 times, then the engine blew. Did you check the oil level and clean the engine cooling fins when you acquired the mower? It would be unusual for an engine with prior damage to take that long to blow, if the problem (nearly always either no oil or clogged up cooling fins) had been corrected.
To look into your problems we need to know the Model, Type and Code of both the original and replacement engines. This will be stamped on the cooling cowl.
