That's what we've done now, but we've tried going up because we didn't know if it was starving for fuel, but made it worse so we've dropped it down to the position where it runs the best, but its still not ok, just better but i cant drop the needle anymore it's on the first setting , using half trottle its ok gets to 65/70 mph ok, but give it full trottle and gets lumpy again... could it be something to do with the air filter being a hi-flow? or the straight exhaust pipes? or fuel pump?? the exhaust on the bike don't look very old could it be that they need to be set for the carbs? or injectors upgraded? I want to get standard exhaust pipes anyway, just going to save some money and try to find some standard exhaust and then maybe book it in to a yamaha garage to try to sort it out,brought the bike home today from work... I had enough with it! we've tried everything we new, even called the yamaha garage and asked for advise and they've told us to do what we've already had done!...
Would like to say thanks for everyones advise and help.