I own a 2005 Lawnboy Gold Pro Dura Force 6.5 Hp. Model 10550. The original coil lasted 4 years. I bought a 2nd ignition coil in 2009 it lasted until May 2017. Not bad. 9 years for that one but cost $55 at a local equipment supply store. Found the next one online for $12 with free shipping from California. I'm back in business. Except for the surging. I totally do a tear down of my mower about every 2 or 3 years. Sharpen blade put in new primer bulb installed external shut-off valve with a filter even though there is one in the carburator bowl. I opened up the meter jet with a slightly larger drill like I read in different web sites even though it ran perfectly all these other years. Not sure what changed other than the low octane gas that you get now at the pump.