lower unit gear exchange 35hp 50hp?

[stutsman18]

I recently have purchased an 1988 50hp force motor and have found out that the gears in the lower unit are bad. Can i replace the lower unit gears with gears from a 1986 35hp force motor? I do know that the teeth on the drive shaft from the 35hp motor is different from the 50hp so i would need to keep the bevel pinion w/bearing but what about the gears below that? any info would be greatly appreciated! thanks!!!!

 

[Frank Acampora]

Re: lower unit gear exchange 35hp 50hp?

Turn the flywheel of both engines one or two turns by hand with them in forward gear. Measure how far the prop turns. If it turns the same on each engine, The gear ratio is the same. If the gearbox torpedo is the same size and the ratio is the same, then yes, they are swappable.