I have a Bolens model 660 riding mower. It's 4 years old. Last week I tried starting it but had problems. It sounded like the battery was dead, so I went buy a brand new one. Hooked it up and now it does absolutely nothing and it is stuck in gear. I cannot get it in neutral for some reason. So this may be a twofold question since it won't start and get out of gear. Possibly if I can get it out of gear it may start since there is probably a safety device, but I really don't know. So any help would be appreciated.
Thanks!

Look under the frame for anything binding... yes it's a safety switch keeping you from starting it in gear.