Sorry for the delay on this one guys, I know a few people have been waiting for me to post this.
"Shimming the needles" refers to the needle valves in the carburetors. The needle is just that..a piece of metal that tapers down to a point at one end. It sits in a hole that is also tapered. As rpms/load vary this needle moves up or down out of the hole, increasing or decreasing fuel coming out of the valve. What this mod does is starts the needle farther up out of the hole, meaning more fuel, and a richer mixture. This is needed if you install exhaust, or an air filter, however, I would recommend this mod even on a STOCK BIKE. My bike has always been a little hesitant to start, and I could not even free rev it until it was warm. After shimming the needle valves my bike starts with no issue, now I don't even have to use the starting enricher (what people refer to as the "choke", even though it isnt one
Ok, so how to do it;
What you will need
- Stock tool kit
- Phillips screwdriver
- Small washers*
*A note about the washers: The washers I used were .025" Thick. They had a 1/8" hole in the middle. Sorry I was boneheaded and didn't measure the overall size> It doesnt matter really as long as it fits inside the spring retainer (read on).
Remove your fairings. If you need help with that, read this post http://www.newninja.com/how-to/removing-the-fairings-(plastic)/
Remove the seat. 1 bolt on each side hold it on.
I will update this step next time I need to remove my tank ;D.
Remove the fuel tank. Sorry, I had an issue with the camera so no pictures of this process, but it is simple. Loosen the clamp and remove the fuel line going into the carb on the left side of the bike. Put the line into a container. Turn the fuel valve to "PRI" and the fuel will flow out quickly. While this is draining unhook the 3 emmisions lines at the front, left of the tank. There is also 1 emmisions line hooked into a "T" underneath the tank. After all the fuel is drained, remove the 2 10mm bolts at the back of the tank. Now slide the tank back and lift up the back of it. Unhook the electrical clip for the fuel gauge, and pull the tank all the way off.
Now we are at the point where we can see the carbs. Remove the 4 screws on the slide cover (black squares on top) with a Phillips head screwdriver.
Some of the screws can be a pain to reach so you may need to use a long screwdriver or an angled one.
With the cover removed you should see something like this...
Now remove the diaphragm, needle, spring, spring retainer and slide all together.
Take the spring, spring retainer (white plastic piece) and needle valve out of the slide. (Spring not pictured here)
Now put the washers on the needle. I used 2 washers per needle, effectively raising the needle .050". You may use only 1 if you don't have any mods, or if you feel the need for even more fuel use 3. The washer needs to fit inside the "feet" of the spring retainer, so it cant be too large.
Now put it all back together.
Insert the slide without the needle (if you do it with the needle in, the needle may get caught and you could damage it). The slide has 2 holes on the bottom. The one in the middle is for the needle, the other needs to be facing the engine side of the carb when you insert it.
Now insert the needle carefully, then insert the spring retainer with the "feet" facing downwards.
Then insert the spring.
Make sure that the slide diaphragm is in its grove, and will not be pinched by the cover. Install the slide cover, making sure you put the spring in the little "knob" in the middle. Careful when tightening down the screws for the cover, it's only plastic.
Ohh, and if this isn't obvious...You need to do this to BOTH carburetors, using the same number of washers on both.
This may seem a little overwhelming or very in-depth just reading it, but trust me, this is simple. I spent way more time removing the fairings and tank than I did working on the carbs. Just take your time, and remember how it came apart.