I use a 21" Craftsman push mower for some real small areas that the exmark walk behind won't fit into. The cut isn't great. It's a new mower. Blades have been sharpened. It's got a 6.75hp motor. However, it doesn't sound like it's running high enough. So I'm thinking that the blade tip speed isn't high enough causing the crappy cut. Just kinda wondering if anyone knows what the average blade tip speed is for a 21" craftsman as compared to a commercial type 21" like a Toro, Exmark, etc.?? Thanks.