Merc 3.0 L 225 HP

[CMC]

I have a 3.0L 225 Carb Merc. w/ a 25" shaft.How can I find out what the Lower Unit Gear Ration is? Thanks

[HP]

I think you mean gear ratio? It's probably 1.75:1... You can go to Mercury's web site then go to parts express. Type your engine S/N in the box. The e-mail comeback will identify the model # and give you the gear ratio and most all other stuff associated with your engine! Hope this helps........Hal(frequent flyer):D

[Raceman]

Or.................. you can put a mark on the flywheel and a mark on the prop and turn the flywheel exactly two rotations and see where the prop is. You may even find it easier to turn the flywheel 10 rotations while counting the rotations of the prop and then do the math.

[HP]

Yep, you can do that too!!

[HighVelocity]

I think you can turn the motor once, and mark cardboard behind the prop [start and end point] and with a protractor figure it out exactly. Good Luck


Ed

[Massbasser]

Or Drop Your Lower Unit, It Should Be Stamped On Top! ;)