20 Seafari w/ 4 cyl i/o

[barnacle]

Otto if I had to guess I would say you should cruise on plane at about 3500rpm and may see a speed of 18mph. Top rpm should fall around 4500rpm and speeds in the upper 20's. If you want great all around performance ask your dealer about a Alpha 4 series prop. These 4 blade props work great on the 4 cylinder engines. Fuel consuption depends on the year of the package but the 4 cyl. no matter what year sips fuel.