Guys, Need help fixing a 1990's Simplicity 12.5 LT 38" Hydro tractor. Tractor has low hours and had full professional tuneup at the dealer last year. Have two issues 1) Front tire needs to be replaced. Has a tear in the side wall. Tips for replacing it at home? How do it do it myself? 2) Tractor was running great last season after professional tune up/carb cleaning. Dealer said it was in very good shape. Unfortunately my it started acting up. My brother said he noticed he was having problems with the seat. When he was riding if he shifted around on the seat it was cutting out. They way he described it made it seem like it was the safety switch on the seat. Battery was replaced last year, new plug, carb cleaned, and wiring harness was throughly looked over by Simplicity dealer. I don't want to put the money into taking it to the dealer again. Need help fixing tire and non start issue on my own. When I last tried to start the tractor it had power and but NO CRANK. NOTHING. It didn't make any noise whatsoever. So should I jump the two wires together on the seat safety switch and see if it starts? If it starts that way, then I can order a safety switch and install it. If that doesn't work, then where do I look? The tire, figured I could jack the tractor up. Take of the rim, remove tire with screw driver. Place new tire on rim with screw driver and then fill it with air. Does this sound okay? Thanks!