A reinforced gearbox cover is worthwhile even for smaller tuning levels from 70cc. The original Minarelli gearbox cover has the disadvantage that the gearbox shafts are only mounted on plain bearings. This means that the shafts are simply plugged into a hole and are lubricated by the gear oil. The Malossi MHR gearbox cover has needle bearings for the gearbox shafts and thus enormously reduces friction losses in the gearbox. In addition, the risk of engine case damage due to knocked out gear shafts or blocked gears is largely excluded.
For the use of Malossi Overranwandlern Malossi has reworked the gearbox cover from the 2008 version, so that this can be mounted without problems. For Polini Evolution converter, however, there is still the need to rework the gearbox cover something.
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Ball bearing: 17x40x12 (C4)
Needle bearing: 14x20x12 / 22x28x16