Honda 250 Four 1960

1960 HONDA 250 FOUR. Many people were surprised when Hondas appeared in the 1959 T.T. with beautifully prepared 125 c.c. twin-cylinder models; more were surprised when Motor Cycling scooped the European Press in September of that year by publishing first details of a 250 c.c. four-cylinder Honda.

This 1959 machine closely followed the layout of the 125 c.c. twin (see previous pages), with leading-link forks and spindly looking frame. But the cylinders of the unit were mounted vertically.
The power unit was virtually a double-up of the "125", with shaft and bevel drive to the gear train of the twin overhead camshafts, but on the four this shaft was on the off-side whereas on the twins it was on the near-side.

Only a few months later the first Honda fours arrived in Europe to race—but they were entirely different! Gone were the fancy forks and in their place the machines wore sturdy telescopies, although these retained the telescopic steering damper fitted between the frame and bottom crown member—rather like some B.M.W.s.

The engine, too, had been redesigned, with its cylinders inclined forwards and drive to the camshafts by a central gear train rather like the Italian 500 c.c. fours. As on the twins, each "pot" had four valves! Much more downdraught had been given to the four carburetters which were now tucked into a recess cut into the fuel tank.
Other changes included the use of a single-leading-shoe pattern front brake, whereas a rather complicated twin-leading-shoe type was employed in 1959.

An incidental advantage of the change-over to gear-train drive to the camshafts was that the clutch, previously shrouded by the bottom bevel-box, was able to be cooled better, a small scoop being fitted to catch air from the side of the motor.

SPECIFICATION
Engine: inclined four-in-line mounted transversely;
250 c.c. d.o.h.c; drive to camshafts by central
gear train. Ignition: coil and battery.
Transmission: six-speed gearbox in unit with engine, final drive by chain.
Frame: spine-type of tubular construction, swinging-fork rear suspension.
Forks: telescopic with hydraulic damping.