Removing slide to get to needles

What is the easiest way to get at the needles??

On what model bike? What year? 2 cylinder? 4 cylinder?

Mikuni carbs?

Just some of the stuff we have to know...

Bob

Sorry, its a 79 kz650c. It has Mikuni pumpers on it. Thanks, Ed

This is a fairly simple job once you have done it a few dozen times like I have:).

Shut off the fuel petcock, disconnect the fuel line and remove the tank.

Disconnect the throttle cables from the carbs. Loosen the carb holders and remove the carbs.

Drain the carbs of gasoline in a container by turning them upside down. The fuel in the bowls will drain through the fuel supply line and vaccum lines. Do this a couple of time to make sure you get all of the fuel out of the carbs.

Set the carbs on a level bench with the float bowls down.

Remove the three small bolts on the top of each of the four carb caps.

You will find an 8 mm. (If I recall correctly) bolt on the pivot point of the throttle shaft that works all four carbs together. To make sure you are removing the correct bolt, lift the throttle mechanism by hand and you will see all of the brass sliders move together.

Look inside the round sliders and you will see two small screws that attach a flat round base plate that connects to the bottom part of the sliders.

Remove the two screws and you will find the base plate will disconnect from the sliders. Swing the base plate upwards and this will allow you to lift the brass slider upwards with your fingers.

Underneath the slider you will see a 3/4 round circlip connected to the needle. Tilt the carbs flat on their sides and the needle should come out. You might need to jiggle the carbs a bit to get the needles to slip out. I would do the carbs one at a time to keep track of everything and make sure they go back into the same place they came out of.

Note which slot 1 through 5 the clips are on with respect to the needle and if you are changing the slots to adjust for lean or richness, make sure they are all in the same slot positions.

These 3/4 circlips can bend very easy and they must be flat to work properly.

Simply reverse the process to put the carbs back together. You might find that putting the two screws back in through the base plate might be a bit tricky but with the slides down at the bottom of the carb body they will go in if you slightly rotate the base plate to match up with the slider screw openings.

Don't forget to re-check that the 8 mm bolts are connected properly to work the four carbs together. Do a test by moving the throttle mechanism (where the big spring is connected) up and down. The sliders should all move together.

It never hurts to make sure that the carb cap gaskets are in great shape as you don't want your carbs to leak on a hot engine.

Put the carbs back on the bike making sure that they are snugged in tight inside the rubber carb manifolds. Tighten the carb holders, reconnect the throttle cables to the same position they were before and check for proper throttle cable action.

Once you are satisfied that the carbs are connected properly, reinstall the tank and the fuel line to the petcock. Turn on the the fuel supply and let the carbs fill for a few seconds then hit the fun switch.

You should be good to go.

BTW, here is a simple graphic that might help with respect to the clipping settings on the needle.

Cheers-Colin Firth-Ontario Canada

Yep, that's how you do it. BUT, it a lot
easier if you remove the bolts from the
arms that lift the slides.

Also remove the bolt in the bellcrank
(the thing the cables attach to).

Then take off the little black caps at the
end of the long shaft that goes thru all
the arms. Pull the shaft out.

Now, you can lift each slide out with the
needle still attached to it.

When you remove the two screws down in
the slides pay attention to the order that
things are in. One of the washers has a
dimple in it that must be placed back in
the correct position.

Its all really very easy, once you do one
carb you're practically an expert.

When you get it all put back together check
in back here for a few hints on how to get
the carbs bench sync'd before they go back in.

I hope you have a manual....

Bob

I do this quite a bit and remove the carbs from the bike to remove the jet needles in most cases. Just makes the process easier with the carbs in hand. I then remove the spring and remove the five 5mm bolts from the bellcrank and slide actuators and the stop plate between the 1 and 2 carbs. Remove the end caps and slide the shaft out; pull out the slides and remove the two 3mm screws using a JIS screwdriver. These screws will strip easily using a standard SAE phillips screwdriver. After reinstalling, the stuff in pretty much the same order, resync the carbs. Anytime the slides are removed from the rod, the carb sync will be off some.

Excellent, I actually figured it out last night, but that tip about removing the entire rod will make life easier for the last 3. I will sync the carbs once thier back in the bike. What about the set screw with the lock nut on it, it appears to set the slide height at fully closed? What should this be set at, and measured where? You guys are awsome, thanks alot, Ed