Join Date: Aug 2010
Location: Elk Creek, Kentucky
I have stated I change plugs at extended intervals in other threads, 20,000 for standard variety and 50,000 miles or more for iridiums.
However, I failed to add, I typically pull the first set from a new bike on time. I do this to gauge the fueling efficiency of the bike by inspecting the plug insulator color. Once I am confident they look like they are burning well, I either put the original plugs back in if they are easy to change or the bike comes from the factory with iridium to begin with. If the plugs are hard to replace, I swap to iridiums at the first check and go to longer intervals.
Modern efi will fire anything these days. Iridium just lasts longer. However, I have pulled plugs from very lean running machines to find small pieces of insulator missing. This can happen with an engine that is getting coolant in the cylinder also.
So, be certain your bike is healthy before running such long intervals.
2007 Blue SuperVee 1000
2013 Grey Super Te'ne're' 1200
2002 White HD Road King Police (divorced)
2000 Red Honda XR 400r
2003 Green Honda Rincon 650 ATV
If it is not broken, it can still be fixed