Reply To: OMC 30 vs 35 hp

[Mumbles]

If all of the mechanical parts are the same, pistons, carb, head, etc. the power output may be determined by the alignment of the ports in the cylinder liner to the runners in the block. I’ve seen this done on other motors where the liner was cast or pressed  into place with the ports partially blocked off lowering the power output. A cheap and efficient  way to make different horsepower rated motors in the same family without having to manufacture different and expensive parts.

Remember, a motor has to be able to breathe to make power and if it can’t breathe properly, it just isn’t going to make the power it’s capable of.