Pump Drive Belt Tension Check Diagram
The belt tension is checked by its deflection between the generator and pump pulleys or between the pump and crankshaft pulleys. With normal belt tension, deflection A under a force of 10 kgf (98 N) should be within 10–15 mm, and deflection B within 12–17 mm.
To increase the belt tension, loosen the generator mounting nuts, move it away from the engine and tighten the nuts.
(The source is on the website: VazBook.ru)