I have inherited a Craftsman LT 4000 from my sister who had bought it used. I spent some time getting it ready and yesterday finally got it running. It runs fine, but engaging the mower deck takes all I have to shift and when I get it into position the belts do not turn the blades, is there a way to adjust or tighten up the belts, I'd really like to use this mower. Also I have not been able to find a manual for this machine the model # is 917257652. Any help would be greatly appreciated.