Here is the New Model L.H. 200 CC COLT

01 Engine

Aluminiumcrankcases housed a single bush on the timing side and one ball-journal as the drive-sidemain. These supported a built up crank assembly with a roller big-end. The 198cc Colt had bore and stroke dimensions of 60mmand 70mmrespectively, so both differed fromthe 63 x 80 of the BSA C11. Within the timing case cover there was a skew drive to the gear-type oil pump and a single camshaft. An extension fromthe camshaft drove through a seal into an outer housing for the contact breaker mechanism. The camshaft operated levers driving the pushrods that crossed in the tunnel cast in with the iron barrel. An iron cylinder head was topped by rocker assemblies for one inlet, one exhaust valve with a cast aluminiumcover. The oil pump was upgraded for 1955. Ariel also added an additional oil feed to the rockers. Somemajor engine parts are not obtainable, although Draganfly can help with refurbishment, including an exchange upgraded oil pump service. Oversize pistons allow rebores up to +60 thou. Carburation was by Amal, a 1 ⁄ in carburettor, 276 for the first year of manufacture, then a 376Monobloc for the remainder of production. Draganfly notes worn carburettors can be reclaimed, but amodern pattern replacement may well be a better long-terminvestment.

02 Transmission

The sheet steel primary chaincase, secured by many small screws, was another established BSA feature. The pressed shape gave clearance to the crankshaft-mounted alternator and the clutch assembly, driven by a single row primary chain. Roger Gwynn notes the Colt’s parts bin nature means this is a heavier duty itemthan the final drive chain. The clutch hub was supported on a roller bearing and contained the vane-type shock absorber. The three-spring clutch had two plates with friction surfaces and two plain plates of different thicknesses. The gearbox was a GB30 made by Burman, but the Colt used a specific mainshaft as it took drive fromthe BSA manufactured clutch. From1955-onwards, themethod of clutch adjustment changed from the clutch pressure plate to the opposite end of the gearbox, requiring a different pushrod. Gearboxes of this type were redesignated GB33. Unfortunately, the gearbox was not as robust as other Burmans. Restoration can prove

difficult, asmany of the parts that give problems are no longer available, even gear and kickstart levers. A popular option is to substitute an entire BSA gearbox.

03 Electrics

The six-volt systemwas Lucas, but subject tomore changes than just about any other part of the Colt’s production run. There were four different wiring looms, but Draganfly can supply all but the earliest version. The lights, switches, ammeters (where fitted) and other Lucas-supplied parts are all available, mostly as pattern replacements.

04 Cycle parts

The frame was a singletube open-diamond, with suitable lugs for the bolted-on rear plunger sub-frame. The front hub had cup-and-cone type bearings, with a singlesided brake drum. The rear hub was the same as a Bantam, complete with brake drumand combined sprocket, but revolving on ball journal bearings. Both hubs were laced intoWM1, 19 inch rims. The tinware includedmudguards, chainguard, fuel tank, oil tank and battery carrier. Many of the cycle parts came fromBSA’s C10L and Bantamranges and are still available, even includingmuch of the tinware, but with the exception of the fuel tank.

05 Suspension

Rear suspension had plunger units linked by the wheel spindle, again, standard BSA practice rather than the Anstey linkmethod once favoured by Ariel. With compression and rebound controlled by undamped springs, it was basic stuff. It also suffered if greasing was neglected, but replacement parts are still available. More typically Ariel was the well-padded, colour-contrasted dual seat that added a little more comfort. At the front end, the Colt got a relatively substantial pair of oil-damped telescopic forks. These are also BSA, but fromthe C11. The great advantage with so much commonality of parts is that somuch is still available.