Okay first off I want to wassup to everyone.

Okay I have a 2006 zzr600 with like 7200miles, I bought it used and starts and runs fine. Changed the oilwith Valvoline 4 stroke oil.Anyways I have in whatI guess isa huge problem and its when I shift to 5th and 6th gear the bike begins to like shake nasty up and down. (example) its like going through alot of speed bumps but at a fast speed. The funny thing is that it start shaking like this when I begin hitting 40mph and aboveplus it doesnt want to accelerate it hesitates alot when I try to go at high speed. I mainly ride in the street andI'am afraid totake it inon the freeway because of this problem.This usually happens when there is a lot of wind hitting me. I dont know what it could be if I might have to clean the carb or air filter or shocks etc... Please I need help its my only means of transportation.

PS: I'am sorry if could not explain it right but its a really weird experience and I tried to explain as best I could

 

does it feel like the engine is doing it? if not it sounds like a wheel horribly out of balance

 

I have no idea, unbalanced wheels are all that I could think of. I think bad alignment could cause it to do that as well.

 

Hmm you know what I never really thought about the tires but I doubt it because it usually happens when there is a lot of wind like if the wind is going north and im going south it begins to shake but if I go with the the wind its fine. But I believe its more the engine becuase when I try to give it gas at 40mph it doesnt want to go so I let go of the throttle and try to maintain the 40mph.

I will try to make a video

 

going into the wind rams air down the intake. could be running lean and getting detonation (pre-ignition)

 

it won't be unbalanced wheels. I don't balance mine at all after changing tires and I never have a shake what soever.

Now a bent front rim will definately do that.
Also make sure your two hoses are hooked up to your ram air just below your headlight.
If they are not on properly then your float bowls will not pressurize properly and your bike won't carbuerate at about that speed and above.