I gotta ask because it happened to me. I did the hydraulic tensioner upgrade on my 2006 with the oil pump upgrade. Put it all back together and it wouldn't start. I checked everything, pulled both plugs out trying to see spark, nothing. I went back to the book and noticed a small note says basically that you gotta have one plug in for the thing to fire. After several hours of wasted time sure enough we screwed one plug back in and the other fired like a champ, pulled that one out screwed the other one in, both plugs firing. Grrrr. Did I feel dumb. Anyway I opened the cam case back up, rechecked timing and I had screwed up lining the timing marks when reinstalling cam gears. Lined it all up right put it back together, installed both plugs, bang started on the first touch of the button.
So make sure you've got one plug screwed into the cylinder when testing the other for spark.