What year?

[tleitch]

I have a mercury 25xd with a ss 6534121. Is there a way i can find the year of it?

[Lostknight]

I looked here.

MODEL YEAR CHART MERCURY OUTBOARD 25-40 HP 2-CYLINDER -- Mastertech Marine

and by it, your motor is an 1984.

Could be wrong, but thought I'd try.