no balancing carbs wont make a blind bit of difference to how its fueling although it wont hurt to do them as it will run a tad smoother on tick over and low revs personally i would spend a bit on getting it set up on a dyno it would cost you up to £200 and thats all in the bike will be set up with the air filter and end can if you have one and will run 10 times better and have a really smooth power delivery all the way through the rev range and it takes the guess work out if you fit bigger jets you could just end up masking a problem ie the jets might not be big enough but make it run better but it still lean which could in the long run hole a piston and dead motor or you could just be throwing loads of fuel in if the jet is too big also the needles might need adjusting too all this is way too complicated just by guessing and riding