f90 - c85 90 lower unit compatibility

[cyrillefrenchy]

hello yamaha experts
do you know if a lower unit from 85 or 90 2 stroke would fit on a F90 with the same drive shaft lenght .
would it be the same gear ratio and the same strenght?
it is to rebuild a spare lower unit for a f90 and i have hard time to find good used parts for that, 85 and 90 2 stroke lower units parts are easier to find.
thank you for any help
frenchy

[boats.net]

No I don't believe it will, The F90 oil pump is driven by drive shaft and may leak oil using 2 stroke drive shaft.

[cyrillefrenchy]

hello
thank's for the quick answer, i know what you mean, the top of the drive shaft is a little different, it came back in my mind after your answer.
now my next question is : does the internal components are the same or compatible?
it is to rebuild a f90 lower unit who blew up and covered by the warranty, i kept the old one , the main drive pinion peeled off, thorwing chunks of metal and damaged the 2 others and the bearings.i am trying to rebuild this one to use it as a spare for my boat rental business in case another one blow during the busy season, i have 3 f90 and used lower units are hard to find and i like to have spare parts.if someone have any, let me know by private message
thank you
frenchy

[boats.net]

It looks like the F75-F100 gearcase and internal parts are the same but the 2 stroke gearcase and parts all have different part numbers.

[cyrillefrenchy]

hello
thank's boats.net for the answer, it is what i saw on the parts lookup, so i guess i have to stick with F lower unit parts...
merry christmass all
cyrillefrenchy