Need help with year based on serial# 40 hp mariner

[badhabit]

"Serial #OG18582..... My #3 cy

"Serial #OG18582..... My #3 cylinder just went out and I tore down the old motor yesterday. Possible replacement has serial # shown above. My motor was a 40 hp mariner magnum, 1989 model.
Thanks,

FOrgot to mention that the possible replacement powerhead as compression as follows: 1-110, 2-108, 3-100 and 4-108"

 

[galamb]

"Hello Jason, if you have your

"Hello Jason, if you have your model year correct (1989) that would make your serial a 0Cxxxxxx.

If so, the powerhead you mention as a replacement will bolt right up and anything you can scavenge off your old one can be kept as spares.

And the compression numbers on the new powerhead sound decent..."

 

[rmanjar11]

wil like to know what year is

wil like to know what year is mu 40 hp ob mariner the number are 6e9 s 003107?
also will like to know what kind of gear oil should i put in the trans?