2017 Yamaha F8 F8LMHB Outboard Motor

Yamaha's 2017 F8 F8LMHB puts 8 hp through a 197 cc, two-cylinder block on the longer, 20-inch (L) shaft, built for jon boats and dinghies sitting a bit taller at the transom than the short-shaft version of the same motor.

Shaft and mounting

Yamaha also sells this F8 on a shorter shaft that will not sit correctly on a taller transom, so measure first. Mounting centers are 28.6 inches apart, and the helm turns 45 degrees off-center each way with tilt climbing to 78 degrees over 4 trim steps.

Running specs

This is a manual-start motor at 89 lbs dry, with a bore of 2.20 inches and a stroke of 1.57 inches at 8.8:1 compression. Fuel needs are regular unleaded at a minimum 87 octane, with oil capacity of about 0.8 liters, and ethanol content capped at 10 percent. The carburetor is tuned to a 3-star C.A.R.B. rating, and exhaust exits through the propeller using a BR6HS spark plug.

Is cooling automatic? Yes, water cooling with thermostatic control. Does it need a charging kit for an alternator? No, it carries a 6-amp alternator as standard on this trim, unlike the smaller F4 and F6 portables that need an add-on kit. What is the gear ratio? 27:13, or 2.08:1, shifting forward, neutral and reverse.