I am working on a 06 Bronco with an 18.5hp Briggs and Stratton Intek Single Cylinder, it runs pretty well at idle and when easily giving it throttle but if I give it throttle too fast it starts surging, backfiring through the carb and sometimes will recover if I throttle it down or will die. When it dies it will crank and backfire loud out the exhaust once then nothing, pull the plug and it's wet. It will also die like I explained above when engaging the blades. It had a bad compression release and I installed a new camshaft, any ideas. It was surging badly with the old carburetor so I installed an amazon carb on it, that fixed the surging but it still isn't right.