The 5.5 and 7.5 motors are very similar. The challenge they have is the impeller change that requires powerhead removal. Also the slip clutch instead of a shear pin can be problematic. While only a few pounds heavier, the 10HP is really a better motor. Simple impeller change like any other OMC and no slip clutch. Prior to 1958 they have a heavier duty gearcase but I really like how my 58 runs, it weighs only 67lbs. (I monitor the oil level and check it often for any water.) 10HP has great performance on a 14ft boat.
Attachments:
