part of my lower unit is gone from an accident,
i have a starcraft nexstar 2312 5.0 mpi bravo 3 drive
serial number OW184141 but i cant find what lower unit or gear ratio i should buy now?
Any one an idea what ratio the drive is?

Your gear ratio should be on the side of your upper drive housing, Along with your drive serial number, The number you posted is for your transom assembly. TRANSOM serial number: 0W184141 Model number 6211001N1 MERCRUISER BRAVO TRANSOM Manufacture Date: 10/20/2004 And it is NOT REGISTERED with Mercruiser.
Also you will want to know if you have (Design-I) or (Design-II).
(Design-II) has two anodes under the anti cavitation plate.
Also will need to know if you have a normal bravo drive or a bravo X series drive.


https://appcenter.mercurymarine.com/...Locator-mc.jsp

If you can not read the ratio were it is stamped on the side of the drive housing, you can look at the input shaft.
With the drive of the boat. There will be a letter engraved on the shaft(providing the shaft has not been changed). That letter indicates the gear ratio.

B is a 2.00:1
C is a 1.65:1
D is a 1.81:1
F is a 1.50:1
G is a 1.81:1
K is a 2.20:1

You can also mark the input shaft and prop shaft. Then rotate the input shaft to determine how many revolutions it takes to turn the prop shaft one revolution.

thanks for the info