Beta RR250 - Coolant Liquid Pump and Centrifugal Unit

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ENGINE CHECKS AND ASSEMBLY
EXPLODED VIEW OF CENTRIFUGAL UNIT AND WATER
PUMP UNIT
1) Rocker arm;
2) 5x15x2;
3) M5x12 screw;
4) Complete valve control rod;
5) Spring guide;
6) Auxiliary spring;
7) Adjustment spring;
8) 10x16x1 washer;
9) Roller bush;
10) Centrifugal control lever;
11) Water pump impeller;
12) Water pump washer;
15) Complete centrifugal unit;
16) Axial roller cage;
17) Centre bearing;
18) Spacer;
19) Circlip;
20) Complete centrifugal shaft;
32) Ball joint retainer ring;
33) 6x19x6 bearing;
34) 15x32x9 bearing;
35) Oil seal
3.9 COOLANT LIQUID PUMP
AND CENTRIFUGAL UNIT
The water pump must assure the correct flow rate
of coolant, depending on the set rotation speed,
in order to remove the required amount of heat
from the power unit. The centrifugal unit activates
the whole exhaust valve control linkage based
on the engine rotation speed, while springs 6
and 7 provide the appropriate resistance to the
centrifugal action generated by 20, in order to
assure optimal supply of torque and power.
The impeller 11 is keyed onto shaft 20 and
coupling is assured by tightening nut 3 on shaft
20.
The centrifugal unit shaft 20 is supported by
bearing 34 found on the internal clutch cover and
by bearing 33 on the external side right crankcase
half. The seal is guaranteed by oil seal 35