gpz900 engine doesn't sound right... with video

Hey everyone. My roommate picked up a bike last weekend and we just got it running. it runs great but it makes a loud mechanical noise. I'm not sure what it is but I think it might be the timing chain. I am hoping that one of you might be able to tell me what I am hearing. I have included a video with this post. Please tell me what you think. Thank you in advance.

Sounds like carbs out of sync.
Steve

Thanks for the quick reply and sorry about the delayed response. We are attempting to sync the carburetors right now however I'm running into a problem. I understand that there is for vacuum lines that run to the sync gauge however the port on the number two carburetor is vacuum for the gas tank. Is that where I hook up the line for the number two carburetor? I was thinking that that would kill vacuum to the gas tank and fuel would not flow while syncing the carbs. I was able to hook up 3 to the gauges but they are jumping around erratically when making adjustments. There is only 3 adjustment screws while syncing, correct? They are the screws between each set of carbs? Any ideas? Thank you in advance./center]

When you pull the fuel vacuum line just set the petcock on PRIME and it will let fuel through.