This guide applies to the ZR-7 Jet Kit available on our affiliated MotoSpecialties.com web site.  Click here for details.

Contributed by Jarel Jensen

Click here for printable MS Word version (right-click on the link and choose "Save Target As" to save the document to your local PC - size is 1.3 MB, so it may take a while to download).

(Click on pictures to enlarge)

Step 1: Remove the tank.  See the Tank Removal Guide if you don't know how to do this.

Step 2: Remove the airbox.  See the K&N Filter Install if you don't know how to remove the airbox.

Remove the retainer springs by rolling them back off of their grooves on the rubber boots on all four carbs.

Remove the rubber boots on all four carbs by sliding them out the sides.

Keep track of the exact direction that each rubber boot was in when you removed it.  You'll need to put them back in the exact same direction, and if you remember it you'll save the trial and error of getting them lined up properly on reassembly. 

Unhook the quick disconnect fitting on the K-Tric sensor by squeezing in the little tab and pulling the fitting apart.

Disconnect the choke cable from the connector on the carbs.  Push the choke lever on the carbs with your finger to give some slack in the cable.  Then slide the cable end out of the retainer slot.  Once the end is free, you can slide the plastic cable out of the tab that it sits in on the carbs.

Disconnect both of the throttle cables from the carbs.  This is best accomplished with a long pair of needle-nose pliers.  Grab the cable about 1/2" above the connector where the cable end is seated.  Twist the cable with the pliers so the cable will slide out through the small gap in the cable end retainer clip.  This will be easier if you loosen the throttle grip housing on the handlebar first.  I STRONGLY recommend you loosen the throttle grip first, as it will make this job MUCH easier.  Make sure you disconnect both throttle cables.  When you're taking the open throttle cable out, you'll need to push up on the throttle assembly from below with your fingers to give you enough slack to work with.  In other words, you're going to open the throttle by pushing up the assembly in the same way the cable would pull it up if it were connected and you twisted the throttle grip.

Once you've got the throttle cable end out of the retainer, you can just lift the metal cable tube out of it's seat and it will be free.

Turn both of the throttle cables up and out of the way.

Disconnect the vacuum line from the right-hand side carb.

Disconnect the breather lines from both sides of the carb bank.  These are not hooked to anything on the other end, they're just open breather lines, so make sure that when you disconnect them that they don't fall behind the airbox where you won't see them.  You might want to tape them in place as a reminder.

Drain the gas from the float bowl before removing the carbs to prevent gas from spilling on your workbench.  I use a plastic cap from a can of spray paint to catch the fuel.  Just sit it below the drain plug, and loosen the drain screw with an allen wrench.

It's hard to reach the two carbs on the left with the allen wrench, so I grab the end with a vice grip pliers to extend my reach.

Loosen the retainer clip that secures the carbs to the intake on all four carbs.

The carbs are now free from all attachments, so you can just tip them downward to unseat them from the intake boots and slide the entire carb assembly out the side of the engine.  Just do it slowly, and they'll slide right out.  

Place the carbs upside down on a workbench.  Be careful not to smash the two plastic fittings on the top that the breather lines were connected to.  I avoided this by placing the carbs on two small 1" thick pieces of wood, with the leftmost and rightmost carb resting on the wood.  This creates a gap between the two pieces of wood for the plastic fittings to stick down without touching the bench.

Remove the anti-tamper plugs from the fuel adjustment screw casings.  The picture shows one on the left that has been removed, and one on the right that hasn't been removed yet.

Drill a small hole in the center of each plug with a small drill bit and variable speed drill.  It helps to center-punch each plug first with a small nail to get the drill started in the center.  Drill SLOWLY and stop as soon as the bit is through the plug.  It's only about 1/8" thick.  Then screw a small self-tapping screw into the hole.  Grab the screw with a pliers, and pull the plug out.  Do this for all four plugs.

Now that the plugs are out, you can adjust the screws.  If you’re replacing the stock pilot jets with the larger #38 pilots, start with 1 turn out as a base setting.  If you’re leaving the stock pilot jets in, start with 2 turns out.  To accomplish this, turn the screws in all the way just until snug, DO NOT tighten them.  Now keep an eye on your screwdriver and turn the screw 1 full turn out.  Do this for all of the adjustment screws.

Remove the float bowl casing by removing the four screws holding it on.  Use a good sharp screwdriver to avoid stripping the heads of the screws.  Some of them may be on pretty tight, so be careful. 

Now that the float bowl is off, you can see the Main jet right in the middle between the two plastic floats, and the Pilot jet recessed in the cavity next to it.  Remove the Main jet with a screwdriver, being careful to remove ONLY the small jet on top, not the entire brass fitting that the jet screws into.  You may need to hold the brass fitting with a wrench to remove the jet if the whole things starts to turn when you try to remove the jet.

Remove the Pilot jet from the recessed cavity with a screwdriver.

Screw the new Main jets (the short ones) into the brass fitting in place of the stock jets.  Tighten them just snug, DO NOT overtighten them.  Screw the new Pilot jets (the long ones) into the Pilot jet holes.  Tighten them just snug, NO NOT overtighten them.  Then put the float bowl back on and replace the 4 screws.  Repeat the process for all four carbs.

Turn the carbs over so the black caps are pointing up.  Remove the four screws holding the cap in place.  Make sure you're holding the cap down with your fingers when you remove the last screw.  There is a spring under the cap, so if you're not holding it down the cap can spring off.

Remove the cap and pull out the spring that's underneath.  It has a small plastic piece inside the spring that is used to hold the needles down.

Lift out the needle assembly, it has a rubber boot at the top.

Turn the assembly upside down and the needle will fall out.

Place the washers provided in the jet kit on the needles so they slide all the way up to the top of the needle.  The number of washers you use will be either 1, 2 or 3, depending upon your altitude and climate.  For lower altitude and lower humidity, use all three washers.  For higher altitudes, you might only need one.  This is a judgement call, and there is no “right” answer.  If you’re unsure, use 2 washers to start out with.  If the bike runs too rich, you can always take the needles out and remove a washer or two later.  NOTE: This CAN be done on the ZR-7 without removing the carbs from the bike by removing the tank to get access to the needle caps from above. 

If you look inside the carb, you'll see the hole that the needle stick down through.

Put the needle back in the housing, put the housing back in the carb, put the spring back in, then screw the black cap back on.  Make sure that you seat the spring on the round tab in the bottom of the cap before you screw it on.  Repeat this procedure for all four carbs.

Slide the bank of carbs back into place.  Make sure you get them all the way back into the intake boots, you'll have to push them pretty hard.  They should be stuck all the way in as far as they'll go.  Then tighten the band clamps on all four carbs to hold them in place.

Replace the four rubber boots that connect the carbs to the airbox.  This is the most tedious, knuckle-scraping part of the job.  Start with the two inside boots, then do the two outside one.  You'll have to squish them down to squeeze them into the space they go, then reshape them once they're there.  Make sure you get them back in the same direction that they came out.  Once you have them on the carbs, you can roll the retaining springs back up into the slots.

There are little plastic pins sticking out from the airbox at the top and bottom of each hole to help you get the boots back on correctly.  The boots have little cutouts that line up with these pins.

TIP - Stick your hand through the back of the airbox and help pull the boots into place from behind.  This will make it MUCH easier to get them back in place.  I discovered this after spending 10 minutes getting the first boot in place from the front.  The next three went much more quickly.

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Connect both of the breather lines back up.

Reconnect the choke cable by pushing the choke lever on the carbs with your finger to give some slack, then slide the cable end connecter back into place.  Seat the plastic cable housing back in the slot provided.

Reconnect both of the throttle cables.  First slide the metal cable housing back into the corresponding slot on the mounting brackets.

Slide the cable ends back into the slots and make sure they're fully in place and centered in the retainer housing. For the open throttle cable, you'll need to push up on the throttle bracket from below with your fingers to give you the slack you need to reinsert the cable end.  A long needle-nose pliers helps here. 

Reconnect the K-Tric quick-disconnect connector.

Reconnect the vacuum line to the carbs.

You're done with the carbs!!

Tuning:

Now that you've removed the anti-tamper plugs from the fuel adjustment screws, you can adjust them while the carbs are still in the bike by using a small screwdriver from below.  If you need to add or remove washers from the needles, you can do this on the ZR-7 by removing the tank to access the needle caps on top of the carbs.