My 1999 20hp ghs 42" deck walker has not been vacuming leaves like it has in the past. It is leaving small amounts of leaves behinb. I have replaced the belts and blower housing, and catcher screen and there are no clogs. The motor has 1690hrs but seems fine. The deck is slightly worn and some of the baffles on it are bent a little. Even dropping the deck very low doesnt solve the problem. Also the blades are new. Any help would be appreciated.