I bought some Champion Iridium spark plugs, they came gapped at 42. Supposedly that is correct for the Xfire, according to Champion. Most post and the manual say 40, or 38. Has anyone use the Iridium plugs and if so, what did you set the gap at(?) and how are they performing?

 

I got the iridiums from Rob at Needswings, pre-gapped to 40.
They have been running 4 years now, no complaints.