Special Rubber Ball for the crankcase breather. Suits Laverda 350/500/7501000/1200 and other models.

Soft compliant NBR Rubber: Oil/Fuel/Petrol Resistant.

WARNING: The rubber ball needs to have some softness to seal properly. e.g. If the ball doesn't bounce to approximately 300mm when dropped from a height of 1metre it will not be resilient enough to seal or create the required negative crankcase pressure. In some cases the positive crankcase pressure created from a faulty (or absence of) ball will blow the large gearbox seal out of the crankcases releasing oil onto the rear tyre.

Negative crankcase pressure is necessary to prevent oil leaks and increase power.