A Low-Cost Power Solution for Rising F4 Tunnel Boat Racers
Mercury Racing® boosts its support of circuit racing with the addition of the 60 APX model to its Apex series of pure competition outboards. The 60 APX is designed specifically to power catamaran tunnel hull boats in the UIM F4 class. The F4 designation was chosen for the first UIM circuit-racing class powered only by a low-emissions four-stroke outboard. The F4 class is very popular across the U.K., Western Europe and the Middle East, and the 60 APX was introduced on February 28 at the Dubai International Boat Show at Dubai Harbour, United Arab Emirates.
The F4 class is intended for young racers starting out in enclosed tunnel boats before stepping up to faster F2 and F1 boats. The 2023 F4 champion, 24-year-old Jarno “Jape” Vilmunen, of Finland, was 12 years old when he started powerboat racing in the SJ-15 class, then spent six seasons in the GT-30 class, winning the Finnish championship in 2017 and 2018. In 2024, Vilmunen will move up to a faster F2 class boat. The 2022 F4 champion, Stefan Arand of Estonia, finished third in the 2023 UIM F2 World Championship. The 22-year-old racer will step up to the premier UIM F1H20 World Championship in 2024.
“Mercury Racing is excited to support the sustainable future of circuit competition with the low-emission four-stroke 60 APX model,” said Jeff Broman, Director, Mercury Racing. “These young racers are often backed by a team of family members, and, while this is a professional class, keeping the cost of participation manageable is important. We’ve designed this motor to deliver strong performance with minimal maintenance over the course of a full season.”
The F4 class features composite, driver capsule-equipped boats measuring 3.9 meters (about 12 feet, 10 inches) in length with a minimum weight with driver of 360 kg (793 pounds). The Mercury Racing 60 APX outboard will push these boats to a top speed of about 120 kph (75 mph) on the straightaway sections of the course.
The 60hp, 995cc 60 APX four-cylinder powerhead is based on the rugged and reliable Mercury 60hp FourStroke outboard with electronic fuel injection (EFI). The WOT rpm limit is raised to 6000-6400 rpm, and the motor is fitted with a 15-inch midsection and wing plates for the side steering system used on competition tunnel boats. The 60 APX model uses a stock Mercury gearcase with underwater exhaust and a 1.82:1 gear ratio. Dry weight is 112 kg (247 pounds). The motor produces full power on affordable 90 RON (87 octane) pump gasoline.
New Mercury Racing Apex graphics match those of the 4.6L V8 360 APX and 3.4L V6 200 APX four-stroke competition outboards – the outboards these young racers hope to be piloting in the future.
