Thanx for everyone's help I've blown the air line down every hole there is bk to front and front to bk two many times it's still hanging around 4000 aswell as the exaust glowing. I've also put new rubbers around where the Carbs join each other together thinking that could be where air gets in and checked the rubbers where the Carbs sit on thanx

this sucks man you checked carb screw orings and balencing them, to check for odd balls!?

Is the blanking screw still in situ?

thanx for the replys from everyone im goner try this when i next got to see the bike thanx