CHEK 125 c.c. – MODEL A
When the engine fails to start, and when you find that the spark plug keeps fouling, it is usually because there is a high tension leak in the spark plug wire spring contact holder (Part No. 200-02/23). This is the hard rubber or bakelite part that screws into the left side of the crankcase near the magneto.
This high tension leak can be eliminated by making a direct contact with the high tension wire at the terminal. To do this, first cut off the lower portion of the contact holder at a point 3/8” up from the lower edge. Then drill a hole down through the remainder of the holder to a size which will give a tight push fit for the wire.
It will be necessary to cut and spread the spark plug wire as shown also . Assemble the holder nut, holder casing and rubber ring on the high tension wire. Push the wire through the contact holder, screw the contact holder in the crankcase, push wire into place firmly, push the rubber ring and holder collar down, and tighten the holder nut.
The spark plug wire forms the insulation rather than the contact holder and, in most cases, you will find that the engine will start readily and no further spark plug fouling will be experienced.