Yamaha 25 hp lower unit rebuild

[fshndad]

Hello guys,

I've got a 25 hp yamaha 4 stroke that has the forward gear missing 2 teeths.

If I replace the forward gear, would I need to re-shim it or could I just pop the new gear in?

[99yam40]

did you even think about replacing the pinion also?
It meshes into the that gear that is missing pieces

[boscoe99]

If the new gear is manufactured precisely to the dimensions of the old gear, no.

If the new gear is not precisely manufactured to the dimensions of the old gear, yes.