If you are really on a budget you can tweak your carbs just a little bit without even removing them and spend less than 50 bucks. I got 4 Hp and a smoother running bike with a better power curve with the following.
First go down to your local bike shop and order a K&N replacement filter for around $40. Stop at radio shack and get a little pack of washers that they sell for around $1. If you dont have a 3/16" drill bit and some masking tape pick that up while you are out.
Remove your fake gas tank cover and both the sidescoops. Remove the air filter lid and drop in the K&N filter. Since you are retaining the stock needles DO NOT remove the little Y shaped piece on top of the airbox. By doing so you will end up with about 1 more HP on top but you will have a big hole in the middle of the powerband that you dont want.
Now go to the four little square carb covers that stick out the sides just below the fake scoops. Unless you have a special torx socket you can plan on breaking loose and replacing the one funny looking screw with a pair of vice grips or other creative method. This is an anti tamper screw to keep you from messing with your carbs per uncle sam. The other 3 screws should be easy for you. Do the covers one at a time as we do not want to mix up the slides between the carbs.
When you pull one off you will find the following. The cover, a spring, and a slide assembly with a diaphram attached to it. Be very careful with the diaphram and notice the little O ring between the outer cover and the carb body. Be sure you put it back on reassembly. Set everything aside and concentrate on the slide assembly. Look down inside the center hole and you will see a plastic screw that holds in the needle assembly. Remove and set aside the plastic screw. pull out the little spring and the needle assembly. Pull the little plastic piece with the little tit on it off the front of the needle. find one of the appropriate sized washers in the radio shack washer pack and insert it under the plastic piece you just removed upon reassembly. It goes between what you just removed and the clip on the needle. What you are doing here is raising the needle up in relation to the position of the slide. This will have the effect of richening up the midrange slightly.
There are 3 things to be careful of upon reassembly. First make sure the little plastic tit seats into the little hole in the slide when you drop it back in. Second when you put the plastic screw back into the slide you need to make sure the needle does not set up tight in the slide. It needs to be loose and able to move back and forth a little. You will probably have to take a little bit off of the bottom of the plastic screw in order to keep this from happening. Third notice that the diaphram only fits in one way. Do all 4 this way.
Now we are going to adjust your idle mixture screws. Take the 3/16" drill bit and wrap the tape around it about 1/4 " from the end of the bit. This is to keep you from drilling too far when we drill out the plugs. Just below the little dohicke (technical shit this is) that sticks out from the covers you just put back on you will see a plug that we need to drill out. Drill it and then use a little screwdriver to pop the rest of it out.
Now you have access to your Idle mixture screws. They are probably set somewhere around 2 turns from bottoming from the factory. Check and record where each one was when you started. As you bring them out the mixture is going to get richer. Try starting them around 3 1/2 turns out. I actually ended up with mine about 4 turns out. This makes the Idle too rich (sounds kinda cool though) but improves off Idle throttle response and driveability. You can set it for a smoother Idle but your driveability and throttle response will not be as good with the stock needles.
When you ride your bike you should notice better throttle response and a harder pull up top. If it had a popping thru the carbs coming off idle that will be gone. You should be able to do this whole job in about an hour and a half with minimum tools and experience. I have since gone to a different setup with a Factory products jet kit but thats another story......Roy