| MODEL | VELOCETTE KSS MK I AND II AND KTT MK I - V 1925 - 1948 |
| Year | 1925 - 1948 |
| Engine Type | Four-stroke, single cylinder, overhead camshaft |
| Displacement / Capacity | 348 cc / 21.3 cu in |
| Bore X Stroke | 74 x 81 mm |
| Compression Ratio | 7:1 (KSS, KTT Mk I-III) |
| Cooling System | Air |
| Max Power | — |
| Max Torque | — |
| Ignition | Coil |
| Induction | Amal carburettor, twist grip |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | Dry sump |
| Gear Box | 3-speed hand change (KSS); 3 or 4-speed foot change (KTT) |
| Clutch | Wet multi-plate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Open frame, engine as stressed member; single cradle on KTT Mk V |
| Front Suspension | Webb fork with adjustable spring-loaded dampers |
| Rear Suspension | Spring-loaded seat |
| Front Brakes | 7 in internal expanding drum |
| Rear Brakes | 7 in internal expanding drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | 711 mm / 28 in |
| Wheelbase | 1365 mm / 53.75 in |
| Ground Clearance | 108 mm / 4.25 in |
| Dry Weight | 120 kg / 265 lb |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | — |
| Rear Tyre | — |
| FUEL SYSTEM | |
| Fuel Capacity | 8.5 Litres / 2.25 US gal |
| Fuel Consumption | — |
| Top Speed | — |
The KSS (Super Sport) was the sports-roadster form of the overhead-cam 350, built for clubmen and with or without lights. The KTT racer followed in 1929 with a positive-stop foot gearchange, and Mk II to V brought cam, head, compression, frame and gearbox changes; the Mk V's cradle frame improved handling.
