Yamaha F4LMHA Outboard Motor. 20-Inch Shaft Carbureted Tiller Handle Manual Start Manual Tilt Gray. The Yamaha F4LMHA is a small but capable 4-horsepower outboard designed for boaters who want something light, simple, and easy to manage. It's a go-to choice for dinghies, inflatables, and small fishing boats where portability matters just as much as performance. With a 20-inch shaft, it works well on boats with deeper transoms, and the manual start makes it straightforward-no batteries required..