2018 Yamaha F90 Midrange Mechanical 25 F90XB Outboard Motor

Yamaha's 2018 F90 Midrange Mechanical, model code F90XB, is the extra-long-shaft, 25-inch version of the 1.8-liter, 90 hp Midrange four, nine pounds heavier than the shorter-shaft version at 362 lbs dry simply from the longer housing and driveshaft.

Shaft length matters here

This 25-inch rigging suits a taller transom than Yamaha's more common F90, so measure carefully before ordering. Remote mechanical steering needs a matching cable and control box, and electric start is standard on this trim.

Power delivery

Four valves per cylinder and a single overhead camshaft keep the block compact despite the larger displacement, and stainless steel drive, prop and shift shafts sit under a five-layer anti-corrosive paint process with multiple sacrificial anodes added for saltwater protection.

Trolling and capacity

Idle speed can be dialed from 550 to 1000 rpm in 50-rpm increments through the Variable Trolling RPM Switch. Trim adjusts -4 to +16 degrees, tilt reaches 70 degrees, and oil capacity runs 3.2 liters with a filter or 3 liters bare. A built-in Freshwater Flush Device lets the engine flush without starting it.

What is the full-throttle ceiling? It lands close to 6000 rpm, the same band as the shorter-shaft F90. How much current does the alternator put out? Up to 35 amps, three-phase. Is electric start standard? Yes, electric start comes standard on this 25-inch trim.