Unit c identification

C15 & C25	249cc OHV. 67mm x 70mm

Sept 1958	C15 Star introduced, unit construction engine and 4 speed gearbox. Amal monobloc carburetor, telescopic forks and swinging arm frame, 17" wheels, 6" full width hub brakes, 21/2 gallon tank, rectified lighting, dual seat, points behind cylinder.

February 1959	C15 Scrambler introduced, Scrambles version, high compression motor, undershield, upswept exhaust, short seat, fork gaiters, ball ended control levers, no lights. C15 Trials introduced, Trials version, medium compression motor, undershield, upswept exhaust, optional lighting system.

April 1961	Sports Star 80 introduced, Sports version C15 with high compression motor, 3 gallon tank, clamped handlebar controls.

September 1961	C15.29839 + CSS.1101 Engine C15.3180? Frame larger capacity Lucas RM18 alternator, detachable ignition key instead of switch, new dual seat.C15S.3101 + C15T.1451 engine C15S.3601 Lucas RM19 alternator fitted.

1962	Horizontal outlet fuel tap.

May 1962	C15S.3320 Engine C15S.10001 Frame, C15 Scrambler now known as C15S Scrambles Special, as previous C15S but with 7" front brake, expansion chamber exhaust system, 2 gallon alloy petrol tank and mudguards as standard, strutted handlebars. C15T now known as C15T Trail Special, trials version of C15S Scrambles Special except strutted bars and expansion chamber exhaust.

September 1962	C15S Scrambles and Trial, duplex frame and seat tubes, new steering head, central oil tank, in board exhaust and air cleaner, no longer known as Specials.

September 1963	C15 roller bearing big end, primary chain adjuster, magnetic speedometer. CSS sports type mudguards. C15S + T front fork gaiters.

September 1964	C15F engine modified gearbox, timing case mounted contact breaker. C15FSS Chrome plated mudguards. C15FS + C15T modifications as C15.

August 1965	C15FSS.1248 Engine C15.4905? Frame Sports Star 80 discontinued.
	C15FS.296 Engine C15.3136 Frame C15S Scrambles discontinued.
	C15FT.515 Engine C15.3136 Frame C15T Trials discontinued.

September 1965	C15F.2089 Engine C15.49001 Frame C15 Star chromed plated petrol tank now standard.
	C15SS.2001 Engine C15.49046 Frame C15 Sportsman introduced, similar to previous Sports Star 80, but with raised handlebars, separate chrome plated headlamp, racing type seat.

August 1966	C15G Star and Sportsman, Victor bottom end.
	C15G 793 Engine and Frame C15 Sportsman discontinued.

November 1966	C25.101 Engine B25.101 Frame C25 Barracuda introduced, sports model similar to Victor Roadster, but with smaller engine. High compression motor, square finned alloy cylinder barrel, plain big end bearing, crankcases similar to Victor Grand Prix, competition type frame with QD rear wheel, 7" brakes, 12volt lighting, glass fibre petrol and oil tanks.

June 1967	C15G.2406 Engine and Frame C15 Star discontinued.

January 1968	B25B.101 Engine and Frame C25 Barracuda now called B25 Starfire.