So I only have had this 455 a couple weeks now and have been through a general maintenance on it. I also did the main engine seal. Mowed today and some other yard stuff. Went to start it and it started right up no issues. As soon as I let out the brake it quits. I pulled the brake switch and it seems to be OK. I taped it in the closed position to get it out of the yard but it just keeps quitting when not depressed. Any ideas where to look?