I have a 10HP OHV B&S on a Generac generator.  It had a filthy carb and would not start.  I took the carb apart and cleaned it, cleaned the plug, put a clean fuel filter and replaced the gasoline.  It cranked right up and runs smooth except it has hiccups.  It will run for 10-15 seconds then have a quick sputter and then repeat this cycle.  Any ideas?