Go
to the Archive indexSome information about the Cymota unit from period sources: The Cymota is a 45cc two-stroke internal combustion engine utilising a deflector type piston. The motor, fuel tank, battery and fixing clamps are mounted on the black back plate (ie ‘the chassis’) and the lamp is mounted in the bonnet (ie ‘the body’), which covers the motor and fits flush against the back plate, rubber beading being inserted to prevent rattles.
| Bore | 38mm |
|---|---|
| Stroke | 40mm |
| Cubic Capacity | 45cc |
| Carburettor | Amal type 308 |
| Main jet | 25 |
| Mixture control needle | in centre slot |
| Fuel tank capacity | 3 pints |
| Fuel | Petroil mixture in the proportion 20:1. The measure attached to the fuel cap holds the correct amount of oil for 1 quart of petrol. |
| Lubrication | The following grades are recommended for summer & winter: SingleShell, Wakefield Castrolite, Mobiloil Arctic, Essolube 20 (ie all grades to SAE 20) |
| Plug | Champion L10 |
| Gap | 0.018" |
| Ignition & lighting | Flywheel magneto |
| Bulbs | Headlamp: 8V 0.5A |
| Parking light: 4.5V 0.3A | |
| Tail light: 6V 0.5A | |
| Battery | Twin cell, Exide C60 or Ever-Ready 800 |
| Contact breaker gap | 0.012"–0.015" |
| Timing | 0.015" BTDC |
Photo: Joost Heersakkers
First published: October 1991
To the owners of the early 45cc VéloSoleX, the engine dimensions of the Cymota look rather familiar being, of course, those of the French machine. In fact the Cymota was a more or less straight copy of a Solex, so close a copy that most of the top part of the engine can be interchanged. The main differences lay in the use of a Miller flywheel magneto - no great advantage when compared to the reliable SEV unit on the original - and an Amal carburettor.
This last did give a power advantage but at the cost of having to provide separate throttle and choke controls. The Cymota also lacks the Solex’s sophisticated, pumped recirculating petrol system, provided instead with a crude tank and petrol tap above carburettor level.
The Cymota did have, as B Roe remarks, a ‘streamlined bonnet’, the main purpose of which was to conceal the Solex-like engine inside. A bonus of this is that if anyone finds a Cymota with bonnet but with a missing or broken engine, then a 45cc or 49cc Solex unit can easily be substituted. It wouldn’t really be any less ‘British’ than the original.
First published: December 1991