Caution! Before refitting head covers, clean head and cover surfaces carefully.
Apply THREEBOND on the head cover perimeter along the gasket housing.
![](https://motoinstruction.ru/img/aprilia/17/123103.jpg)
Apply THREEBOND on the head in the areas indicated in the figure.
![](https://motoinstruction.ru/img/aprilia/17/123104.jpg)
For the remaining operations, follow the removal operations but in reverse order.