I'm experiencing a problem that is bringing me huge headache.
The bike has 62k Km. and I always take care of her, but lately it started running very bad on 4.000-5.000 rpms when I go full throttle.
It vibrates, rattles and it's hard to overpass the 5.000 rpms, but over the 5k it revs very fast, runs smooth and push hard.
I made several check, including rough cleaning of the carbs and I found cracks in the diaphrams of carbs 1 and 4.


I replaced all the 4 diaphrams and now it runs better, but not 100%
I removed the airbox and turning on the engine I found that if I quckly turn to full gas and back, the guillotines vibrate and make the same rattling sound that I hear while riding
I attach a video.
DO you have any idea of what I can check further?