Yes he can you may need to send him a pm. The people on this site dont care if it is gray market or not. You may need to start a new thread on the forum. I would not run it until I found out what the knock is could be simple like oil passages under cover stopped up or you may need to change oil and filter (it could be stopped up if you havent changed that out already). Please start a new forum and everone will jump all over it to help you. handy