Abstract: A four-valve cylinder head of a four-stroke engine has a body formed with an enlarged material cross-section portion located above a combustion chamber to increase heat exchange surface in the cylinder head. For cooling the cylinder head the latter is further formed with a straight passage receiving cooling air therethrough. The passage includes a central portion, a funnel-shaped portion communicating with the central portion, and a conical suction portion also communicating with the central portion. Cooling air is introduced into the interior of the head through the funnel-shaped portion and is sucked away through the conical suction portion.

Abstract: A holding device installable on a motorcycle for supporting saddlebags, lateral baggage pouches or luggage pieces is made of a strong, fracture-resistant synthetic material and includes two lateral holding frames which support upper frames interconnected by a transverse luggage rack. The rear part of the lower side of the upper frames has an extension for supporting transverse fastening screws which are guided in grooves formed in the top side of the underlying holding frame. The upper guiding groove permits the tilting of the upper frames downwardly about a quadrant. At the front end of the lower side of the upper frame is formed a locking nose engageable in a corresponding recessed receptacle in a lateral wall of the top side of the holding frame. By displacing and tilting the holding device, it is possible to swing open the seat of the motorcycle to access a storage compartment below the seat.

Abstract: A supporting arrangement for mounting, for example baggage pouches on a motor cycle, includes two L-shaped brackets each having a longitudinal leg and a transverse leg. The longitudinal legs each is formed with two parallel portions offset relative to one another and provided, respectively with openings or projections. In assembly the projections of one portion of one bracket engage the openings of another portion of the second bracket so that the exposed sides of the longitudinal legs of both brackets extend in the same plane.