Something odd about adding a new spark plug off to the side of an exisitng four valve head. Centre plug, valve angle, piston crown and squish band (shape of the combustion chamber) would have taken years to develop to ensure reliability and durability in the old engine. That must have all gone out the window with the new extra plug in the corner arrangement.
Suzuki has a dual plug- 4 valve head on their M109R and C109 motors (109 C.I. v-twin) Since 2006. Obviously a big displacement difference but at least they have a reference.
2012 DL1000 Adventure (Tinkerbell)
PC-V, TRE, CR8EIX , ECM, K&N, RDL, PR4, PC-8, EB H4, WERKS, Madstad 22", 17/43 gearing, AdventureTech: Fork brace, shelf, mirror extenders, SpeedoDRD, wheel spacer, Head's-Up voltage monitor, Goldwing pegs, Sonic 1.1. Wolo Bad Boy.