Bought a used one yesterday but after trying it out today on the first snow of the season, I'm not sure it's working right. I bought it hoping my 13 and 12 year old boys could run it around the neighborhood but it seems to push pretty hard. Wheels turn freely but it's the front edge that scrapes along pretty hard. Are the blades supposed to be 5/8 inch above the ground? Are they worn more than usual? I thought perhaps the blades would make contact first and sort of act as a help to pushing. I'm ignorant. I've never owned one except for one my grandpa bought me back in the early 80s. If I need to change the rubber blades, is it a pain and where is a good place to find parts?