seats. If there is any wearing of the metal the valves should be ground until the surfaces are perfectly smooth, so that an absolutely tight joint is made on the seating. Sometimes the ignition plug is not properly screwed up, and this should be looked to; there should also be proper packing between the plug and the cylinder at the junction. One of the most important places to look for leaks is at the piston-rings. These are set in grooves on the side of the piston, and make it fit tightly in the cylinder. On account of the excessively high temperature inside the cylinder, which dries up the lubrication, the rings may not run well, and will allow power to be lost, particularly if the engine has been out of use for a time. A little paraffin dropped into the cylinder through the compression tap will ensure free and proper operation of the piston-rings. The petrol motor is a very economical producer of power, unless something like a leak or bad ignition is taking place, and while really simpler than a steam engine, it seems more difficult of comprehension to the budding motorist.
The owner of a motor cycle who expects to use it constantly without previous experience, and not run up against various sources of stoppage and breakage, will find himself mistaken. A frequent experience is to run the whole gamut of troubles, and thus by actual knowledge having learned to fix all the various parts, the operator is qualified to take care of his machine. These troubles occur for three principal reasons. First, the ordinary individual who buys a motor cycle will not make a careful study of the manner in which the machine is built and how it works, but prefers to tackle it on the 'hit and miss' plan and learn by hard knocks and experience. Second, carelessness and the disinclination many persons have to take proper care of a piece of machinery. A motor cycle, however, cannot be expected to run properly unless it receives regular attention. Third, from accidents pure and simple. As already explained, a great deal of trouble might be avoided if riders would only take the pains to understand the principle of the machine before attempting long journeys.
