It sounds like Adrenaline induced hyper sensitivity to me ! and now he is hearing his engine for the first time !
'97 VN1500 91 Cubes Of Custom CLASSIC
Vance & Hine 2to1
engine, forks, ignition & carb mod's
WebCam cam & rockers hard weld & grind
NEW TOP END, NO LOOKS ALL GO GO
Maxx intake manifold system & super G carb 44mm