Toro 283L with 700 hours. I am the original owner. When the fan turns on it almost kills the motor. Seems to get better after it's been running long enough to get hot. Earlier this Spring (It was 80 in March around here.) it didn't have enough power to pull itself up an incline and mow at the same time. I have tried new air filter, new plugs. For a while it seemed better. Today I had about half the yard done before it seemed to kick into full power. I mow a little over 8 acres. As an added symptom I have thrown the belt off the main drive the last two times I started it. This mower has been flawless since I bought it. Any help !!!!!!!