Dont go via Honkong if you are going to Nepal withour having old visa in your passport...you will be in trouble...if one has valid US visa only then he has no problems while going to KTM via hongkong..if you are going to Hongkong with your new passport only then most likely Cathay Pacific will not let you board the plane in the US itself as you dont have valid US visa..easiset way is go via gulf or India but NOT Hongkong at any cost.

Sparrow