I purchased a new Toro Z450 48" TurboForce mower with a Toro twin bagger system. When I start to mow, I run the throttle to the full open position just before engaging the blade system. It seems that the additional startup load of the blower for the vacuum system takes a BIG bite out of the 23 HP Kawasaki engine RPM. I have been told that I can pull the choke out momentarily just before I engage the blades to richen the engine fuel ratio. This does seem to help some but I am concerned that the sudden bite into the engine RPM may be doing damage to my mower's engine. The local dealer did not have much to offer in way of what is normal and what is not normal. Would I have been better off going with Toro's mulching system for this mower? Any suggestions (belt release for vacuum system at start up) would be most appreciated.