GRAUPNER heim UNI-Mechanik 2000 Mode D'emploi page 55

The UNI-Mechanics 2000 system is designed to accept a wide range of motors, and to make
this possible different gears can be fitted in the first stage (see also the table on page 6):
• For normal-sized models with a rotor diameter around 150 cm and a powerful 10 cc two-
stroke motor, a ratio of 9:1 is used. This is achieved by fitting a 24-tooth pinion on the clutch
bell, and a spur gear with 54 teeth.
• For 15 cc two-strokes with rotor diameters of 180 cm or more, we recommend a reduction
ratio of 10:1. This is achieved with a 22-tooth clutch pinion and a spur gear with 54 teeth.
• For 15 cc two-stroke motors and rotor diameters of around 150 cm we suggest the ratio of
7.7:1 in the interests of optimum noise reduction. This is obtained by fitting a 26-tooth clutch
pinion and a 50-tooth spur gear.
Once you have selected the appropriate reduction ratio, you will need to fit either the ring gear
4448.107A (54 teeth) or 4448.107C (50 teeth) on the gear flange 4448.107D. In either case the
gear is secured using three M3 x 10 countersunk screws. Tighten the screws fully, but not so
hard that they distort the ring gear, as it may then wobble when rotating.
First slip the top bearing holder 4448.11 loosely on the shaft (note correct orientation: the
bearing recess in this bearing holder faces up), then fit the top bearing 4448.31, followed by one
shim washer and the ring gear you have just prepared. Line up the cross-holes in the shaft and
the gear flange, and carefully press the roll-pin 4618.65 through both components, but only to
the point where the pin engages in the shaft, so that you can still withdraw it if necessary.
UNI-Mechanics 2000
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