Originally Posted by co46
I have noticed that the 350 horsepower Yamaha out boat is a V8 and therefor weighs 365KG, compared to the 300's 260KG. Thats over 100KGs more, and I wonder is the extra weight (and the extra £££s) really worth it for 50hp, when you already have plenty
There's no substitute for CC's when it comes down to pure grunt, torque, torque torque
The extra 2 cylinders could make more difference getting a heavy boat on the plane compared to the extra 50hp. Outboard hp ratings are derived from the ICOMIA standard which basically means that the HP at the prop has to be +/- 10% of what it says on the cowl, so in theory
a 300hp engine could be 270-330hp at the prop & a 350 could be 315-385hp at the prop. A weak
300hp (270hp) compared to a strong 350hp (385hp) suddenly looks a different (prop)osition (pun intended) Rumour has it that the etec 75hp is actually closer to 81hp & the 90 (same block) is only delivering 85hp & is £500 quid dearer. If you apply the 10% rule to the 75 & 90 you could (in theory) have a 75hp chucking out 82.5 hp & a 90 only giving 81 hp, makes you think dunnit?