6.6. Spark plugs

Fig. 133. The control of an interelectrode backlash of a spark plug by means of lamellar calibre

Fig. 134. Bending of an external electrode by means of the special tool

Diameter of a carving of spark plugs of 14 mm. It is desirable to use candles recommended by manufacturer, in case of need it is possible to apply suitable candles with corresponding калильным number of other manufacturers. As the design of candles often varies, before to buy the new complete set, it is necessary to address always in service centre Volkswagen to learn last information on the admission of products to sale. The interelectrode backlash (fig. 133) candles see in the appendix Specifications and characteristics. For the control of an interelectrode backlash of candles their manufacturers offer special щупы. To choose the necessary lamellar calibre and to insert it between electrodes. If the distance does not answer demanded use 134 tool presented on fig. for bending of an external electrode. For this purpose it is necessary to insert a hook into an electrode and cautiously to bend it.

The interelectrode backlash is necessary for leading up to corresponding value. At backlash adjustment it is impossible to touch the central electrode as its porcelain insulator can crack.

Before to turn out candles, it is necessary to check up, whether there are no extraneous subjects in adjusting nests. In case of hit in a nest of a candle of a washer, a bolt, a stone or other subjects they can destroy valves, saddles of valves or a head of the block of cylinders at the first start-up of the engine.

On appearance of candles it is possible to draw a conclusion on their suitability to the further use, about work of system of injection, a gas mixture and engine condition (pistons, piston rings, etc.).