Jim Newell wrote:

Why are smaller outboard motors water-cooled?

I am thinking 5 - 9 HP engines.

I understand why inboard, inboard/outboard, and larger outboards are
water-cooled; but why are smaller outboard engines water-cooled as well?

Wouldn't air-cooling be simpler?

Simpler, yes, but not my much - outboard water pumps are pretty simple
IME. And air cooled engines are nowhere near as efficient. Air cooled
engines are forced to run richer to maintain low enough combustion
temperatures under heavy loads and high ambient temps. More fuel use,
more emissions. Sitting out on the water, why *wouldn't* you water cool
an engine?

Keith Hughes