I have a JD425 - I think is a 2000 - I mow about 2.5 acres - in 2008 the engine would miss, spit and sputter every once in a while but would smooth right out - I did not have it looked at - in 2009 the problem got worse and happened more often - I replaced gas filter, air filter, plugs, wires and coils before taking to dealer - they replaced the ignitor (electronic ignition?) worked ok rest of the year - 2010 the problem is back and getting worse - I replaced the gas cap, re-gaped the plugs, replaced gas filter and air filter. seems to run better with the gas cap off but its a new cap - dealer did not think problem is in carb but not sure what is left. not a fuel injected unit - any thoughts out there.

thanks