Willie’syamaha

Good day all, I own a yamaha fzr1000 genesis ‘90 model. It was bought from overseas and went thru 4 family members before I owned it. All of the owners and me had one commen problem; the bike struggles to pull away below 3000 to 4000 rpm, I was determined to get it right but failed like all the others, later on the bike developed another symptom where it floods if I rode it in town on stop and go’s but on the open road it is fine. I then recently bought a second damaged fzr where the piston went thru the block but all other spares were ok, so I jumped to the cdi first with no luck, I then reinstalled the exup in the in the exhaust for the pull away problem with no luck. I then went to the carbs, i changed all components from the one carb to the other (floats, needles, jets) all in order, still flooding. I also changed the petrol pump with the exact same pump and two other one’s still no luck. I then got the bright idea to change the needle position because it had a spacer before the circlip, i took the spacer out and the bike stoped flooding but started starving, I then moved the circlip one position forward and now the bike is flooding again.I did synchronized the akumi carburetors, changed the rubbers between the carburetors and the engine, replaced the diaphragms . I just don’t know what to do next Any advice will be appreciated thanks