I like that quote..."inner ear problem"!
I've been searching on the 'net for anyone that has put a small-block in a PWC and can't find...
That's why I thought the Kawasaki Vulcan engine would work fine...they have a few different sizes (900, 1500) that have the Harley sound but...
It's an American thing, you wouldn't understand...:D
I have wondered this for a while...the only thing I don't like about PWCs/ Jet Skis is the "ring-ding-ding" weedeater sound...seems like there...
Try this site---he will sell the .dxf files for CNC cutting, and he has some interesting designs:
Here's my favorite---the Thunderbird built in 1940 designed by John Hacker: