Nice boat, I forgot that Yamaha made I/O's.
Thanks! Yeah, too bad Mercruiser decided on attempting 'world domination' back in the early '90s, because the Yamaha drives, especially the Hydradrive like I have, were pretty sweet. The Hydradrive uses hydraulic clutches and you simply can't believe how smooth it is shifting, none of the noise or drama associated with the cone clutch system like Mercruiser and Volvo have. You simply move the shift lever and you GO. They also go just as well backwards as forward so you can have twins with counter-rotating drives by simply moving a little lever inside the outdrive where the shift cable comes into it.
The only downfall is I have literally found only one guy in the U.S. who can work on them or has any parts, his name is Ken Nelson of Nelson Marine in Panama City Beach in Florida.