The inline four, also known as the straight-four, is one of the most popular types of motorcycle engines. Real-world examples of the inline four include the iconic Suzuki Hayabusa along with others made by BMW, Kawasaki, Honda, and Yamaha. You can find a variety of motorcycles with the inline four and we only put it a slot above the V4 because there are more choices for consumers. 

In terms of pros and cons, the inline four is similar to the V4. It’s heavier, more complex, and more difficult for home mechanics to work on than simpler engines with fewer cylinders. They are also larger overall, resulting in motorcycles with larger dimensions. These are definitely more for cruising highways than crowded city streets. Since they are fairly powerful in general, you’ll typically only find the inline four in motorcycles with high-rated power. They’re also pretty expensive, so they’re not built for or priced for beginner or intermediate riders. 

For the pros, the inline four is an excellent overall engine. Much like the V4, they’re fast, loud in a good way, have low vibration compared to engines with fewer cylinders, and they have a good overall sense of balance. These are the kinds of motorcycles you see flying up and down the freeway in those dashcam videos on YouTube and TikTok. The aforementioned Suzuki Hayabusa set the world record for the fastest stock motorcycle at 194 mph back in 1999, and it used an inline four to do it.