In 1965 Suzuka, Japan; Honda made its racing debut with a 125cc 5-cylinder (RC148) motorbike driven by Luigi Taveri. This Honda engine can run around 21,500 RPM. Honda RC148 Inline 5 Cylinder, 125 cc engine with Top Speed 200 km/h!
During the 1965 racing season, the Suzuki 125 RT 64 has a two-cylinder, 2 stroke engine with rotating disk distribution, which was far more powerful than the Honda 2 RC 146 four-cylinder engine. The Honda people realized this at the start of the season, and they confronted the facts by putting aside the old model and started working with motorbikes that offered something completely new technically.
The results of all that hard work came in 1965 in the Japanese Grand Prix. Honda concocted a 4 stroke, 125cc, inline 5-cylinder engine. Distribution, lubrication and ignition systems do not change substantially. The central exhaust pipe goes through the bottom and appears at the bottom of the saddle. Two cooling radiators installed and it’s placed inside the fairing. As a result, in 1966; the Honda 125cc five-cylinder proved to be the fastest in the 125cc class to ever go down in world championship racing.
Honda RC148 Specifications
Bore x stroke: 33 x 29 mm
Total capacity: 124.8 cc.
Power: 34 bhp @ 20,000 rpm.
Transmission: 8 speed
Lubricant system: Wet-sump lubrication.
Dry weight: 85 kilograms.
Top Speed: 217 kph
The four exhaust cylinders 1, 2, 4 and 5 are in the normal position, left and right places of the bike. Meanwhile, the third exhaust cylinder positions crossed up and around at the side of the engine, across the frame, until it ends under the rider’s right leg.
Currently, the Moto3 four-stroke engine is able to spin up to 14,000 RPM, with 55 horsepower and the top speed that passes 230 km/h but with a much bigger engine size that is 250cc. Meanwhile, the Honda RC148 Inline 5 Cylinder is the only 125cc bike, half size of Moto3 engine, I just can say that this bike is amazing 😉