The Yamaha FZ V3 is indeed a muscular bike, but it can still be suitable for riders of different body types, including slim individuals. Your height and weight should not be a major concern when considering this motorcycle. However, it's important to keep a few factors in mind:
Comfort: The FZ V3 has a relatively upright riding position, which can be comfortable for riders of various sizes. However, since you are on the slimmer side, it's advisable to test ride the bike to ensure that you feel comfortable and in control while sitting on it and reaching the handlebars and footpegs.
Seat Height: The seat height of the FZ V3 is around 790 mm. As you are 5'6", it should generally be a manageable height for you. However, it's still recommended to check if you can comfortably place both feet flat on the ground while seated, as this will give you more stability and confidence, especially when stopping or maneuvering the bike at low speeds.
Handling: The FZ V3 is known for its nimble and agile handling. Its lighter weight and maneuverability make it suitable for riders of different sizes, including those who may be slimmer. This can be an advantage for you, allowing you to handle the bike with ease in various riding conditions.
Overall, the Yamaha FZ V3 can be a suitable option for you, but it's essential to take a test ride to ensure your comfort and confidence on the bike. Every rider has different preferences and comfort levels, so experiencing it firsthand will give you the best idea of whether it suits you and your riding style.