Hello I have a 1988 MTD rider 38 inch cut with a 12.5 BS IC motor. The mower was given to me from my dad who passed away so it does have sentimental value. The tractor looks like new and so I have a question. The carb allowed gas into the oil for a season, it does leak oil from several places, and it seems not to charge the battery. I know its old but how much would it cost to rebuild this engine or too buy another BS motor? the mowes all steel and waxed like a car! Dont like the crap they have at big box stores. thanks