Note: the air box drilling pattern shown in this picture is optional. See Step 14 for details of drilling holes in the air box or air box cover.
6" 2x4
Long #2 phillips screw driver - New, unworn bit, this is important!
Long regular screw driver
Ratchet
4" extension
10 mm socket
8mm open-end wrench
Needle-nose pliers
Snap ring pliers for those cheap-ass vent hose clamps
4" spring loaded alligator clamp ($2 at the home center by the woodworking clamps)
3/8" vacuum plug
2 3/16" vacuum plugs
2 3/4" (I.D.) vacuum plugs (available at your friendly neighborhood auto parts store)
Masking tape
Sharpie marker
Shop towels
3' of 3/16" I.D. clear poly hose
Gas can
Black RTV gasket sealer
Sharp pointy knife
The petcock must be set to On or Reserve - NOT Prime.
There is a nipple on the bottom of each carb. Attach the 3/16" line to each carb in succession with the other end of the line in the gas can, draining the bowl by opening the 3mm allen head drain screw about 5 turns. Be sure the hose stays on the nipple while draining.
Note: This may not get all of the gasoline out of the carbs, but it should get most of it. Refer to Step 8 below for complete drainage.
5 connections.
Remove 2 bolts at the back of the tank. These 2 screws were covered by the front of the seat. Use the 10mm socket.
Lift the back of the tank a few inches and prop it with the 6" long 2x4. (Don't have a 2x4? You can use anything - a clump of rags, a small cardboard box, or even the plastic box that Ivan sent you.)
Unplug the sending unit harness underneath.
The rear vent line will pull loose on its own. (Usually. This is a vent line and should not be tight.)
There is a second vent line forward on the right side of the tank, remove this and slide it out of the retaining clip on the tank bottom.
At the petcock on the left remove the small vacuum line. (It's on the back side of the petcock.)
Clamp the fuel line with the spring clamp to prevent fuel from running out.
Slide back the hose clamp with the needle nose, and slide the fuel line off. If it is a little sticky, use the slotted driver to pry GENTLY between the edge of the line and the petcock fitting to get it broken loose. BE CAREFUL not to damage the line or the fitting. (Note: You can use regular pliers to squeeze the clamp ears and wiggle the clamp down the fuel line about an inch.)
Plug the fuel outlet on the petcock with the 3/8" plug.
Lift the rear of the tank slightly and pull the tank back and off the front rubbers. Note: If the tank does not want to come off of the rubbers you can use a belt sander to make them slightly smaller so they fit the tank slots better.
Set the tank AWAY from the work area on a towel to avoid scratching it if something slips later.
Take out the 10mm bolts on top and slide the covers off the clips.
Remove the 2 phillips screws in the switch housing and pull the back off. Hold the front housing so it does not fall.
The first cable you can see on the back side of the throttle tube is the "open" cable. Its cable housing will have a curved fitting on it. Put a piece of tape on it and mark it "O". Pay careful attention to how the throttle assembly "looks" when it's together.
Remove the front housing.
Remove the cables from the throttle tube.
On the right side of the bike, the choke cable is attached to the choke bar on the front of the carbs.
Push the choke bar to the left to take the tension off the cable and remove the cable end from the fitting. There should be enough slack to do this without removing the cable housing retainer clip.
There are 2 vent lines going back from between the outer and inner carbs on both sides. Pull the lines off, set them aside.
Remove the 2 vacuum lines on the outer carbs.
Loosen the clamps on the intake boots (engine side) with the phillips screw driver.
Use the slotted driver to CAREFULLY roll back the spring clamps on the airbox boots.
Unplug the wire harness for the K-TRIC system.
It is now battle time. Using a rocking motion, slide the carb bank back out of the intake boots and out the left side of the bike.
When it is about halfway out, figure out which cable pulls the throttle open, and tag it.
Now unhook both throttle cables.
Pull the carbs the rest of the way out.
Stuff clean shop towels into the intake boots as a precaution against debris.
There is a nipple on the bottom of each carb. Attach the 3/16" line to each carb in succession with the other end of the line in the gas can, draining the bowl by opening the 3mm allen head drain screw about 5 turns.
Unclamp the fuel line while doing this to ensure complete drainage. Hold the end of the fuel line above the float bowls to avoid spillage.
There is a spring under each cover. Hold onto the cover while removing the screws.
It's safer to do this one cover at a time. The screws are tight: be sure to align the screwdriver straight and push hard while breaking the screws loose.
This is the reason for using a new high-quality screwdriver, and not the 99 cent Chinese one in your wife's laundry room. Stripped screw = Problems.
Lift the cover off and lift out the spring.
Lift out the needle diaphragm assembly (the black boot thing).
Invert the diaphragm and drop out the stock needle and the white retainer. Have a look at the white retainer to see how it fits in the carbs. It must be reinstalled in the same position.
Take a new needle with the desired washer/clip configuration (always 3 washers total per needle) and insert it into the diaphragm, making sure the washers stay in place. There are four grooves near the top of the needle. Your starting point for clips & washers is the third notch from the top, with three washers on top of the clip.
Drop the white retainer over the needle, making sure the hole in the bottom of the diaphragm is visible between the legs of the retainer.
Replace the diaphragm and spring.
Replace cover.
Repeat for each carb.
Remove the float bowl covers (again, one at a time is safer, same deal with the screws, they are tight).
The main jet is the big brass fitting (aka "emulsion tube") between the halves of the split float.
Unscrew the jet with the slotted driver, holding the jet carrier in place (the hex part) with the 8mm wrench. Be CAREFUL - do not bang the floats.
Replace the main jets as needed (2 smaller jets in outer carbs for slip on, four bigger jets in all carbs for full system).
Note: 1100 carbs come from the factory with only one size of main jet. 1200 carbs have large jets in the #2 & #3 carbs. The purpose of the larger jets in the two middle carbs is to give a slightly richer mixture so the engine will not run hot in the two middle cylinders.
You can also use this opportunity to check the float heights. Float height should be considered a base setting. After the carbs are reinstalled you should check the fuel level in each carb. Fuel level checking and setting is described at the end of this page.
Plug the vacuum fittings on the #1 and #4 carbs with the 3/16" caps.
The mixture (a.k.a. "pilot" or "fuel" screws) screws are located on the bottom/front of the carbs in a little "post" shaped protrusion. (Some people refer to these as "air screws" but they actually meter the fuel, so they are "fuel screws".)
There is a small plate covering the screws from the factory, which is held in with some adhesive. The plate can be removed by trimming the adhesive with a knife and carefully prying it out. Drilling is inadviseable. There is no need to replace the plate after adjusting the screws.
Use a small flat screwdriver to turn the mixture screws all the way in until they touch bottom. Don't crank them down tight. Just turn them slowly and gently until they bottom.
Then turn each screw out 3 full turns. You'll fine-tune these screws later.
Plug the hole with the red plug in the kit, using a LITTLE black RTV on the threads.
Put the side cover back on.
Remove the air filter cover. Use the 10mm socket and ratchet.
Replace the air filter if necessary (stock filter only with Ivan's kit). Note: You can use a K&N filter, which allows more air into the carbs, if you do not use all 12 holes as suggested by Ivan in his airbox drilling instructions.
Drill the air filter cover per Ivan's template. (Unless you're using a K&N filter. If using a K&N filter drill only six holes in the air box. You can always drill more if you mixture is too rich.)
OR
Drill the top of the airbox per the picture. Be sure to remove the air filter if you are drilling the top of the air box.
It works better with a new bit. Trim any ragged edges.
Replace the filter cover.
Replace the battery box cover.
Pull the hoses off the housing (not the valve cover), and remove it.
Cap the valve cover hoses with the 3/4" vacuum plugs.
The vacuum lines leading to the #1 and #4 carbs will come off with the reed valve housing. Discard these.
Roll the air box boots back over themselves, and make sure they are rotated properly, and the edges are seated on the airbox. They have a notch in the lip which mates to the rim of the hole in the airbox, and they can be dislodged during the violence of carb removal.
Some people like to tape the boots back, and slide the tape out after the carbs are in. In this case you will need some duct tape.
Check to make sure the intake boot clamps are positioned properly (they also have mating notches), and aren't bent. I bent 2 of mine getting the carbs out. If they're bent, take them off and "re-round" them with the pliers.
PULL THE RAGS OUT OF THE INTAKE.
Slide the carbs in halfway
Reinstall the throttle cables, making sure the cables go on the way they came off. Make sure the curved housing ends stay oriented toward the front or the housing will be damaged.
Slide the carbs in the rest of the way, make sure they are fully seated in the intake boots.
Tighten the intake clamps.
Straighten the throttle cables as the carbs go in.
Reconnect the choke cable.
The choke cable housing retainer fitting should be attached with one of the top screws of the carbs.
Replug the K-TRIC harness.
Remove the tape (if used) and roll the airbox boots over the carbs.
The springs can be replaced pretty easily with a screwdriver and rolling them from underneath with your fingers. If this is difficult, a special hooked tool is available.
Replace the airbox side covers.
Replug the sending unit harness.
Replug both right side vents
Reinstall the vacuum line to the petcock.
Install the tank mounting screws.
Take the plug off the fuel outlet and reinstall the fuel line.
Reinstall the upper fuel line clamp
Replace the seat.
Put the petcock on PRIME, wait 1 minute.
Put the petcock to ON.
Start the engine.