I just bought a Mini Fastrak 42. Model 927350 Ser no. 06062211 with 250 hours. only to find it has a bad EZT on the drivers right side (right motor?) I believe it is bad because the longer you use it the worse it does. After 10 min it won't pull small hills or run straight without the driver looking like he is always trying to make a hard left zero turn. This is my first zero turn and I am totally &@$$ off. Tire pressures are good, belts are like new. Please help, my questions are.. 1. Does this sound like the correct diagnosis? 2. Is there a rebuild kit for this or will it have to be replaced? Parts #? 3. If replaced, Should the other side be done at the same time or wait for it to fail? It feels very strong. 4. If replace both, since there are several Fastrak models can I replace both with better units that can be serviced? Parts #? Thank you for any assistance.