BSA Motorcycles 1950s


Hints on Tuning and Assembly of the B.S.A. 650 c.c. A10 Engine

Compiled by Eddie Dow

MANY changes have taken place on the A10 engine since its introduction for the Gold Flash in 1950, with a steady improvement ia power output, culminating in the Rocket Gold Star manufactured in 1962 which produced 50 b.h.p. The R.G.S. is already tuned to a high degree and the object of these is notes to help owners of older models to obtain an improved performance. It is not advisable to increase the power output from a very old engine, especially if it is proposed to use the machine for racing purposes, because the possibility of fatigue failure of the more highly stressed components.