Please check your engine carefully.
HP and WEBRA parts DO NOT interchange
Don't confuse HB and HP engines... HB engines were produced in Germany by Helmut Bernhardt Feinmechanik and had PDP, Blitz and Stamo models. HP (Hirtenberger Patronen) engines were produced in Austria and U.S.A. They have Gold Cup, Silver Star and VT models. These two engines are completely different and no parts interchange.

Early HP Gold Cup and late Silver Star .61... Early Gold Cups have a smaller rear bearing, crankshaft and front housing with bearing I.D. measuring 15mm - .590"Ø. Use rear bearing, crankshaft and front housing for silver star if you have this older version. Late Silver Star .61 engines used larger 17mm - .670"Ø. rear bearing. If you have this version use Gold Cup parts.

Rotomix carburetor... Early Gold Cup and Silver Star 61's used a barrel type carburetor similar in design to a Perry. Later versions use a slide carb. Parts listed are for the slide carb. Call if you need Rotomix parts not listed. The complete carb (80-0101) listed is the K.61 carb which fits the HP 61 perfectly and is sold as original equipment on the new Silver Star .61's.

Dykes and conventional rings... A dykes type ring is "L" shaped and is located at the very top edge of the piston. A conventional ring is flat or square shaped and is located about 1/16" below the top edge of the piston. Click here for more details on rings

HP engine - exploded view engine screw set prop nut prop washer prop drive prop collet bearing front cover gasket bearing crankcase crankshaft gasket rear cover cylinder connecting rod cylinder head head head shim piston ring teflon pad teflon pad wrist pin piston muffler gasket muffler screw muffler screw strap-on screw strap-on screw muffler, strap-on carburetor piston & cylinder carb neck O-ring needle valve