So under acceleration upto 6-7000rpm the bike chugs along with no power, after 7000rpm the acceleration smooths out but accelerates very slowly.

By chugs i mean, rough acceleration, front end vibration, no power.

The idle is rough once off the choke and bounces about 1000rpm. I reckon this is an air leak in the carb rubbers as i have sprayed carb cleaner whilst it is idling and the revs raise significantly. Front rubbers are new OEM and rear are new Non OEM. so will replace the rear ones with new OEM ones

Would the air leak in the carb rubbers cause the extreme loss of power?

Everything that needs replaced, tested and synced has been done carbs electrics etc etc all ok

Would the air leak in the carb rubbers cause the extreme loss of power? Possibly/probably

Before looking for problems elsewhere repair the air leak first, it will suck air before fuel.

I'd also want to be sure that the intake and airbox/filters etc are standard.

Does it rev OK in neutral? Only under load you have issues?

I have replaced all carb rubbers with brand new OEM ones and the carbs are seated correctly so should not be any air leaks at all now.

it hunts for the idle up and down by 500rpm and when the throttle is blipped it bogs before reving, but it revs fine after that smooth and to the redline.

The airbox is unmodified brand new hiflo air filter. Carbs were ultrasonically cleaned so are spotless, rejetted to 118 in the front and 120 in the rear for the aftermarket can. All new o-rings for the carbs too. the carbs are bench synced with advice from Rick, and the pilot screws 2 1/4 turns out.

Underload upto 6-7rpm it still chugs with the like a vibration front end then after 7rpm it's smooth.

Also it is reluctant to start after it dies or you switch it off, after 15-20 mins it will start again though.

Fuel flows freely from tank?

I'd suggest the carbs need to come off again.

The fact is the intake rubbers have to be positioned in a certain way to ensure they sit correctly. If by spraying wd at them you get the idle to change tells me they are not.

Dumb question.. Do the headers heat up at the same speed..
Start from cold bike, using a hand pump dispenser just spray each header with water at the same point. you should get the same 'hiss'....
If not, first pull that plug..

So Update.

I had the VFR racing last weekend and after another late night chasing my tail it's running alot better. Well power wise it pulls as it should. The spade connectors that connected to the coils from the loom needed pressed together as they were pretty loose and a new set of plugs and boom pulls like a train.

Still struggling with starting when cold and also still hunts the idle (probably just a syncing issue. I also noticed during the end of races it struggled on the power and would go back to it's old ways of not pulling on acceleration power. I thought this was a fuel issue as it only happened 2nd half of the race so ran a full tank and it still did the same. I will do the fuel tap mod to see if this will help.