Gear ratio determination

alldodge

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Might be over thinking this but the ratio doesn't add up so I'm missing something.

Original Drive B3 2:0 ratio so it should have 32/27 uppers and 16/27 lowers. I know the lower has 16/27 gears because I rebuilt the lower section a few years ago

After the repower, I bought a complete brand new B3XR 1:81 ratio drive. Boat would barely come up on plane with 22 pitch props. So I dropped the lower, and installed my original 16/27 lower. Boat comes right up and all is sort of good, for the most part. Doing some research I'm only seeing the XR upper with gears of 16/19. Using the 16/19 upper and 16/27 lower it comes to 1:42 ratio. This just doesn't add up so there must be other gears used in the upper. When I manually rotate the drive, there is 2 upper rotations to 1 lower, so it is a 2:0 drive, and must have something like 32/27 gears in the upper.

Anyone know of Merc listing other gears for the upper?
 

alldodge

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Got it figured out, Merc is listing the upper drive gear set as 16/19, when in fact it is 19/16.
Using 19/16 the calculation works out to original 2:00
 
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