objectManager.events
.add(['mouseenter'], function (e) {
objectManager.objects.setObjectOptions(e.get('objectId'), {
preset: 'mark-hover#icon'
});
})
.add(['mouseleave'], function (e) {
if (!myMap.balloon.isOpen(e.get('objectId'))) {
objectManager.objects.setObjectOptions(e.get('objectId'), {
preset: 'mark#icon'
});
}
});