The carbs are exactly the same, it’s a common myth that the 90 has different carbs from the 75hp. The jetting is different but the venturi are the same.
The physical differences are the 75hp had a low compression cylinder head and restricted exhaust tuner.
80hp had high compression head, restricted exhaust.
85hp low compression head, unrestricted exhaust.
90hp high compression head, unrestricted exhaust.
The later 75hp may have had the high compression head fitted.
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