Even tuned bikes will pop occasionally. To "tune" the popping out, you actually have to de-tune the bike in places. Here's a link to a well-written article that does a good job of explaining everything -> http://www.vtxoa.com/forums/showthread.php?t=21749

 

I increased the gap in my new plugs from.038 to .040 and it does not seem to decel pop anymore.