Gear Ratio's

[fisha63]

Can someone explain to me the pros and cons of low and high gear ratios...just for instance the Yam 60 has a gear ratio of 2.33-1 and pushes a 17 in pitch large diameter prop and the Merc 60 has a gear ratio of 1.64-1 and pushes a 12 in pitch small diameter prop. I've heard the usual things like larger slower turning prop, better holeshot etc, smaller faster turning prop more slippage less torque steer etc.....I know these two motor's have about 100cc difference in capacity and this may contribute to the gearing but what are all the other reasons #concerning gear ratios.....thanks all #:-/

[murf]

are you talking about 2 or 4 stroke?
60 hp 4st Merc, 995cc, 2.31:1 gear ratio on the Bigfoot
been told that the power head is a Yam on the Merc 60?
13.5" prop 14'pitch on 4.75 tinny C/C
interested in response to this question that you posted about hole shot.
Murf

[Noelm]

as a general rule, the lower the ratio the better, as a slower moving larger diametre prop is far more efficient than a small fast moving prop, (like on a ship) BUT of course there are exceptions like in racing applications and the like.