Gear on Mercury 225 CV

[laurent.k]

Hi everybody,
i'm trying to maintain my Mercury Optimax 225CV following an oil leak.
I have uninstall the gear housing and i have found a problem :
The Gear (ref : 43-828169) has one broken tooth...
Can i change all the gear with this gear ? (new ref : 824986) ?

Thank you so much for your reply

sorry for my english i'm french

[laurent.k]

Is it possible to pass from a ratio of 1,75 to a ratio 1,87 ?