I have a 74 Wheere 20ft pontoon and was wondering if a 85hp would be to much or to heavy? Not sure the year of motor, think its a 79 serial #1578945, Kiekhaefer Mercury 850. Also its a 6 cyl.
Depending on which model you have, it's either rated for a 50 HP or a 65 HP. Also, if the serial number you gave is correct, that would be a 1963 model Mercury 850..
Diplomat is rated at 65 HP Sportsman is rated at 50 HP
