19HP BRIGGS INTEK V-TWIN ENGINE W/TRACTOR - (pennsburg in Allentown, PA

Here is a scotts riding mower. 19hp 42 inch cut. Starts and runs good. Just rebuilt the carb. This is a briggs and stratton intertek v-twin 19hp motor that runs. The model number for the engine is [removed phone] the type is 0137e1 and the code is [removed phone]yg. Tractor will go in reverse and forward but after about 10 minutes she slows down and winds. Thinking