2017 Mercury 9.9 HP 9.9MLH-CT Outboard Motor

Mercury built the 9.9MLH-CT around its BigFoot gearcase, pairing a 20-inch long shaft and pull-cord start with a taller, high-thrust lower unit rather than the standard gearcase used on the lighter 9.9MLH sold alongside it.

Why the extra weight is worth it for some boats

BigFoot gearcases trade a bit of top speed for more bite at low RPM, which matters for wider or heavier boats, sailboats running this as auxiliary power, or anyone using it to troll or hold position rather than race across the water at speed.

Still simple to operate

Start and tilt stay fully manual on this model: a pull-cord starter and a ratcheting tilt lever, with nothing electrical to maintain or charge between outings. The 20-inch shaft matches standard-height transoms rather than tall or shallow ones, and a single grip on the tiller manages steering together with throttle and shift.

What to check before buying

Confirm your transom height against the 20-inch shaft, and decide whether the added low-speed push of the BigFoot gearcase actually matters for how you plan to use the boat, since the taller lower unit does add bulk and a bit more drag at speed compared with the plain-gearcase version sold alongside it.

Common questions

Does this use the BigFoot gearcase? Yes, turning a larger four-blade high-thrust propeller.

Is tilt manual? Yes, ratcheting manual tilt.

What shaft length is fitted? 20 inches.

Specifications