I've got a 2001 Snapper Hi-Vac model 219907/0131 E1 with the 12.5 Briggs & Stratton OHV and I use it to cut about 6 acres of grass. I bought it brand new and it has done fine for many years only changing the oil and replacing the clutch. I was cutting the other day and the motor started lagging like the throttle was pushed too far forward and the choke was closing, so I tried throttling back a bit, and that wasn't the problem. It died soon after. I replaced the fuel filter, spark plug, cleaned the stater and magnet on the flywheel, and that gave me a bit more spark, but it still won't start. Any ideas?