Mercury 9.9MLH Command Thrust FourStroke

This used Mercury 9.9MLH Command Thrust FourStroke is a 9.9 hp, two-cylinder outboard on a 20 inch shaft, steered with a tiller and started by hand.

Specifications worth knowing

Fuel delivery is carbureted and full throttle spans 5000 to 6000 rpm, with the gearcase geared at 2.08:1. Shallow water trim range is rated at 16 degrees, and the onboard protection system watches for low oil pressure and over-rev conditions.

What to check before buying

Shaft length here is 20 inches, so check it against your transom height before ordering; there is no remote-control option, since this is a tiller-steered unit. Confirm the exact gearcase fitted on this unit with us before ordering.

What it's good for

As a kicker or primary motor on a small boat, this size pairs well with light aluminum hulls and inflatables where a heavy-duty low-speed gearcase is not a priority.

Who it suits

Mercury built this for small craft: jon boats, utility hulls, soft-hull inflatables, sailboats, and aluminum tiller rigs, with ratcheting manual trim and a through-prop exhaust that keep the install simple with no hydraulics involved.

Condition notes

This unit is sold used, so expect wear consistent with a pre-owned outboard rather than the finish of a new one; have it inspected and run in the water before you count on it.

Common questions

Is this electric start? No, starting is manual, matching the MLH designation in the name.

What size is the remote fuel tank? Mercury lists a 3.2 gallon (12 liter) remote tank as standard for this engine.

What oil and fuel does Mercury call for? 87 octane fuel with up to 10 percent ethanol, and Mercury FourStroke 10W-30 oil.