Lawn Tractor Question

I would say it is the fuel pump if it has one. If not sounds to me you got a restricted fuel pasage some where. Follow the fuel. Or take it to the shop and follow the money. Shame it worked good for 10 years until they put their fingers in there. If they serviced and change filters without cleaning the whole tractor first. I would say they got dirt in somewhere. was this thing clean as new when you got it back after paying them for a new tractor. Take the carb apart your self and check the passages by blowing carb cleaner though the passages both ways or watch them do it. They usually only add the kit and pray for the best. could be dirt in the fuel pump check valve also.