Mercury 3.5MH FourStroke Outboard Motor

This used Mercury 3.5MH FourStroke is a manual-start outboard with a 15 inch shaft and 360 degree tiller steering, built for light duty on small boats where weight matters more than horsepower.

Why the short shaft

At 41 lbs dry weight, this is one of the lightest motors Mercury makes, and the 15 inch shaft suits small craft like aluminum tillers, jon boats, soft-hull inflatables, and sailboats, rather than the longer-shaft setups meant for deeper transoms. The single-cylinder four-stroke pulls 5000-6000 rpm at full throttle.

Practical details

A 4-point mounting system aims to keep vibration low across the rev range, the 1-liter integral fuel tank keeps the footprint small in a tight boat, and a freshwater flushing port clears salt and debris from the engine after use. The long multi-function tiller handle puts throttle control within easy reach. Fuel system is carbureted, cooling is water-cooled with a thermostat, trim is manual with a 16 degree shallow water range, and the gearcase runs a 2.15:1 ratio.

Condition and coverage

As a used motor, expect wear consistent with its history. Five years of coverage apply in total, the usual 3-year Mercury warranty extended by a further 2 years through Product Protection Gold.

What boats suit a motor this light? Mercury lists aluminum tillers, jon boats, soft-hull inflatables, and sailboats as good fits for the 3.5MH.