Re-Power w/ new Suzuki 90...

[FishStretcher]

There is a 150 hp tower of power for sale locally, and the thought has me interested. But I don't think I need to replace a 86 Yamaha with a 74 Merc.

Providing you're running the ADI electronic ignition, you're going to get marginally better performance from the Merc, than you are from the Suzuki. The Merc also weighs 50 lbs less at 296 lbs. The downside is that the Merc can use 30-40% more fuel, and that mixed two-stroke fuel costs more than the straight gas for the Suzuki, too.

That being said, the inline 6 cylinder "Tower of Power" motor is far and away my favorite outboard motor. With the right Boysen reeds, ported pistons, right carbs and jetting and free exhaust, the 89ci/1450cc liter 115 Mercury can produce 200 hp, and do it reliably. You just can never run it between 6500 and 7000 rpms. 9000 is okay, but run it at 6800 and it will self-destruct from harmonics. (I used to run a 1500XS 150 hp at 80+ mph on my 14'10" Cacci Craft, which was a Checkmate V-mate copy. The boat was named "Kamikaze Express")

Tim "Bigshrimpin" posted some amazing test results from Land n Sea from these motors a few years ago, including taking the big displacement version (the 99ci/1600cc 140/150 hp) and making it produce 240 hp at 9200 rpms.