Lower Unit Gear Ratios ?

[Mike Prickett]

:confused: :confused: Need some advise and info on a lower unit and gear ratio change - I am changing the lower unit on my 2007 Merc 250 XS from the TM it now has with 1:62 gears to a SM - thinking of going to 1:75 gear ratio - The motor is on my Bullet 21 XD with a 14 in Rapid Jack plate. Need info on the differences as to hole shot , top end performance , load carring capability ETC. Any info will be greatly appreciated ! :)

[THE FAST ONE]

Seems Like Lot Of Expense,for Hole Shot.prop's Might Be Less Expensive.depends On What You'are Trying To Accomplish.--ed

[hsbob]

what you need to do is calculate the prop speed your now turning. if you using a 30and up prop then youmay want to go higher the the 1.62 to say 1.5[if available]. if your using a 22 then the 1.75 or 87 maybe the way to go. what really matter is getting the gear ratio in a good prop selection/availability range.

land and sea had a paper on their web site that discussed the ratio/torque consideration in detail.