Ssmith wroteI remember buying the factory OEM replacement Champions back in 1993 for $20 US, and they had to be imported from Italy. My neighbors sure were happy when I finally received them. That meant I could stop "burning" the bad plug clean by riding around the neighborhood at 8000 rpm with my burned out Ferracci CF mufflers. Ah, to be 26 again.....
Finally got the NGKs (with the 18mm hex) out. Not that they ran poorly but I did not like the PITA it would be to change plugs with that big a socket in the narrow towers. Got a set of the QVs delivered for about $22. (
www.sparkplugs.com). Bike seemed to run ~5%C cooler but I could not tell if it was the plugs or the coolant flush. No cleaning the plugs with 8K RPM flybys as the bike has the competition megaphones and they are pretty loud!