I have a troy Bilt Pony M15008. It is equipped with a B&S 5.0 HP engine model 135292. This unit has set outside for several year. I have changed the oil, air filter, pre-filter & spark plug. It has fresh gas in the tank. I have cleaned the linkages as well. The issue is that every time you throttle up or put it under a load it bogs down & dies. I do know that it needs a new coil (dog chewed the spark plug wire). The flywheel was very rusty. I took a wire brush on a drill and got the rust off the magnet areas. Any suggestions would be appreciated!