I dont think the yamaha that was posted was a 3cyl. I think it was just 2 stroke. It would've been a good deal if it was. There was an 01 yamaha 3cyl on craiglist for $2,000 a few days ago.
Yes, i have seen the mod. Ive been keeping an eye out for a 35 to try it. Here's a guy who did it. Pretty good read
http://www.tinboats.net/forum/viewtopic.php?f=4&t=23898