a story of a chickensh*t and a dirty Bank O' Carbs

I would be that chickensh*t.

So I've removed the float bowls and all jets from my '78 kz1000 carbs bank. I dunked the carb bowls and all jets in a can of Berryman's carb cleaner, okay the jets and the floats and bowls are all ready for re-installation.

But when I started to remove the individual carbs from the bracket that holds the 4 carbs together I had a sensation of "Oh, hey there, LOOKIT ALL THEM OTHER PARTS I GOTTA REMOVE ta get them carbs off'n this here bracket. Uh-uh. Think I'll leave 'em be, and just spray some carb cleaner here-n-there."

I chickened out and have not removed the carbs from the brackets. I doused the carb bodies top and bottom with carb cleaner.

Not sure though if I'll get away with this!

There was about 8 years of dried crud in the float bowls and the drain plugs at the bottom of the bowls were stuck on them bowls real tight now. So the carbs were mighty in need of a cleaning.

My concern is the innards of the carbs won't be thoroughly cleaned. Especially the long brass pipe that sticks down from the bottom of the carb body into the float bowl --- what is that brass tube? When I took off the float bowls I noticed it sticking downward, a long brass tube with a small pinhole at the very end where
it must be sucking up gas -- for the idle jet?

I'm going to stick a small guitar string into that hole to make sure it's not blocked, I believe it's for the idle jet?

How can I be sure to get the carb bodies clean while they're attached to their home plate rack? And what *is* that long brass tube sticking down into the float bowls? It's not the main jet or pilot jet I'm talking about, it's a skinny brass tube with a single hole at the end that sits in the gas in the float bowl -- what is that brass tube there?

just take them completely apart and soak them or soak them while on the bank. They are much less intimidating than they seem. Don't be afraid!!! Your pilot jet holes are probably clogged and there are a lot of other tiny holes you'll need to blast out with air and soak in solvent. Go all the way and get some rebuild kits, it's easy.

Here's a write up about one way to clean the carbs:

Carb Cleaning 101

By M. Shively

The elements of internal combustion engines are: correct fuel/air ratio, spark at right time, adequate cylinder compression.

There are many passageways and openings to check and clean. All are important in function and when obstructed or not working properly, have subtle to radical effects on engine performance. Vacuum leaks and carburetor synchronization also effect performance and should be inspected and adjusted following the below procedures.

Carb Cleaning 101
Warning: Remove all rubber parts before you begin. These parts usually include vacuum diaphragms, needle valves, o'rings, hoses, and other parts. Spray cleaners will damage these parts. Do not disassemble individual carbs from the carb bracket.

Air & Fuel Passageways: Trace and learn individual fuel and air circuits from beginning to end. Machines can only drill straight through the cast passageways. To change direction, another angled passageway must be drilled. The union is plugged with a brass or bronze bead. Inspect and clean each passageway with spray cleaner, brushes/pipe cleaners/etc, and compressed air. Remove any discoloration and debris. Look for spray cleaner to exit from one or more passageways.

Jet Cleaning: Inspect jets by holding to light and look through them. You should see an unobstructed round hole. Clean the jets with one or more of the following: jet cleaning wires, soak solutions, carb spray cleaners and compressed air. Re-inspect jets after cleaning and install when clear of obstructions. Some main jets have paper-like gaskets. Most have metal spacers between the jet and the emulsion tube. Some screw directly into a brass emulsion tube which is machined for a 7mm wrench at its float chamber exposed base.

Inlet Fuel Valve: Inspect the needle valve & spring. Press down the tiny metal rod that protrudes from the butt or float end of the needle valve. The spring should move freely and return the rod to its location. Check the needle valve's seat area for a groove or other wear. It should appear highly polished. Some needle valve seats are rubber and wear may not be visible. Inspect the needle valve jet seat. You can clean the jet seat with Q-tips and semi-chrome polish if necessary.

Carb Body Castings: Blow air through the atmospheric vent holes located on the dome of each float bowl chamber. Air should exit via hoses or brass nipples. Inspect the emulsion tubes and passageways (cast towers that jets thread into) for discoloration and debris. Clean interior emulsion towers with a soft bristle gun cleaning brush. Clean each Venturi (main carb bore).

Needle Jets & Jet Needles: Clean the needle jets, jet needles, and passageway or tower that needle jet screws into. Clean the emulsion tube (pipe between needle jet and main jet) (Main Jet may screw into emulsion tube). Jet needles are part of the throttle slides. See below…

Throttle Slides: There are several types of throttle slides: Mechanical linkage, vacuum, diaphragm, and cable. Disassembling the jet needle from the slide is not always required for cleaning. If you have vacuum piston type throttle slides (large diameter solid metal slide), avoid cleaning the lubrication from sides and caps. If piston type check cap vents and passageways with air. Clean if necessary and re-lube. If you have rubber vacuum throttle diaphragms, inspect for dry-rot, defects, and tears by gently stretching rubber away from center. Do this until all areas around diaphragm have been inspected. Replace any defective part as described above. Clean carb body areas around diaphragm including air passageways and air jets. Diaphragms have a locator loop or tab fabricated into their sealing edge. Observe this locator upon reassembly. Avoid pinching the diaphragm when reinstalling caps.

Fuel Screws: Fuel screws have sharp tapered ends. Carefully turn one fuel screw in while counting the turns until it seats lightly. Warning: These screws are very easily damaged if over tightened into their seats. Record amount of "turns-in" and remove the fuel screw, spring, washer, and o'ring. The fuel screw is part of the enrichment (choke) circuit...clean passageways as described above. When carbs are assembled, spray low PSI compressed air into diaphragm air vents located at intake side of carbs. Throttle slides should rise, then fall when air is removed. Lightly lube external moving linkages. Reinstall carbs and follow through with carburetor synchronization.

Throttle Cables: Lubricate cables periodically. If cables are disconnected from carbs or removed for replacement, etc . . . remember cable routing and ensure proper reinstallation routing. Avoid bread-tying, sharp bends, and pinching cables. Adjust cables so throttle grip has about 5mm of play or throttle slides or butterfly valves may not open completely (full throttle)(wide full open).

Float Bowls: Inspect float bowls for sediment, gum or varnish, crystallization, and defects. Clean all pipes, tubes, passageways, and embedded jets with cleaners and compressed air. Remove and clean the drain screw and area. Inspect bowl gasket and replace if necessary. Clean and inspect overflow pipes and tubes, look for vertical cracks.

Floats: There are several types of float materials: plastic, brass, black composite, tin, and others. Handle floats carefully. Avoid bending, twisting, denting, or other means of mishandling. Most floats are adjustable by bending a small metal tab near the float axle end. Do not change the float adjuster tab unless tuning fuel service levels. Clean metal floats by soaking or by spraying cleaner and wiping clean. Other material type floats may require replacement if cleaning is necessary. Inspect the needle valve (float valve) and seat. Check needle valve's spring loaded pin. It should depress and return smoothly and without resistance. Check the needle valve's tip for a worn groove. Replace needle valve and seat if either symptom exists. These parts wear together and must be replaced as a set.

Synchronization: This is a fine adjustment performed usually and preferably with the carbs installed and the engine running. The unusual part is performed with gauged wire with the carbs on the work bench. Carburetor synchronizing balances Venturi vacuum at the exhaust side of each carburetor, resulting with smooth idling and optimized performance at all throttle openings. Synchronization is checked using a set of gauges which are either air vacuum type or liquid mercury type. The gauges are connected to vacuum ports on the intake manifolds via nipple tubes or if sealed with screws, sync gauge adapters will be needed. With the engine running at temperature, and with a fan or means of forced convection aimed onto the engine, the carbs fuel screws and idle are adjusted, then the synchronization is adjusted via adjustment screws on the carbs. A reserve fuel tank is recommended for convenience of accessing carbs during this procedure. See gauge instructions and repair manuals for detailed use of synchronization gauges.

Notes: While carbs are apart, record the jet sizes. Look for a very small number imprinted on the body of the jets. Verify that numbers are the same for all jets on models with in-line cylinders. A few transverse-4 models and V-engines, the inner and outer carbs use some different size jets and it's important to not mix them up. If you have dial or veneer calipers, measure and record float heights. Perform measurements with floats just touching needle valves, though not depressing the needle valve rods. Replace fuel and vacuum hoses. Be sure to use fuel rated hose for fuel. Install or replace in-line fuel filters. It's a good time to remove and clean interior petcock fuel filters. Inspect carb manifolds for dry-rotting, inspect all clamps and air ducts. Inspect, clean, lube, and/or replace air filter(s).

New/old. The brass tube extending from bottom of float bowl & up, is the float chamber over flow tube. it allows fuel to escape via external nipple at bottom of float bowl to earth after float valve/s fail. (hopefully before draining raw fuel above throat level and into intake/engine.) period VM's work very well clean.unfortunatly getting them clean is often a chore. at a guess, Your' @ 1/3d the way there. unless in pretty much constant use, deposits build-up in carb bodies, especially in pilot circuit. complete dissassy often incur as many probs as simple cleanings. when possible, i try to avoid unsettling racks. Many bits are un-atainible, get a manual. figure it out. stock jeting is a great base for most applications. luck g

MFolks wrote:

Here's a write up about one way to clean the carbs:

Carb Cleaning 101

By M. Shively

The elements of internal combustion engines are: correct fuel/air ratio, spark at right time, adequate cylinder compression.

There are many passageways and openings to check and clean. All are important in function and when obstructed or not working properly, have subtle to radical effects on engine performance. Vacuum leaks and carburetor synchronization also effect performance and should be inspected and adjusted following the below procedures.

Carb Cleaning 101
Warning: Remove all rubber parts before you begin. These parts usually include vacuum diaphragms, needle valves, o'rings, hoses, and other parts. Spray cleaners will damage these parts. Do not disassemble individual carbs from the carb bracket.

Air & Fuel Passageways: Trace and learn individual fuel and air circuits from beginning to end. Machines can only drill straight through the cast passageways. To change direction, another angled passageway must be drilled. The union is plugged with a brass or bronze bead. Inspect and clean each passageway with spray cleaner, brushes/pipe cleaners/etc, and compressed air. Remove any discoloration and debris. Look for spray cleaner to exit from one or more passageways.

Jet Cleaning: Inspect jets by holding to light and look through them. You should see an unobstructed round hole. Clean the jets with one or more of the following: jet cleaning wires, soak solutions, carb spray cleaners and compressed air. Re-inspect jets after cleaning and install when clear of obstructions. Some main jets have paper-like gaskets. Most have metal spacers between the jet and the emulsion tube. Some screw directly into a brass emulsion tube which is machined for a 7mm wrench at its float chamber exposed base.

Inlet Fuel Valve: Inspect the needle valve & spring. Press down the tiny metal rod that protrudes from the butt or float end of the needle valve. The spring should move freely and return the rod to its location. Check the needle valve's seat area for a groove or other wear. It should appear highly polished. Some needle valve seats are rubber and wear may not be visible. Inspect the needle valve jet seat. You can clean the jet seat with Q-tips and semi-chrome polish if necessary.

Carb Body Castings: Blow air through the atmospheric vent holes located on the dome of each float bowl chamber. Air should exit via hoses or brass nipples. Inspect the emulsion tubes and passageways (cast towers that jets thread into) for discoloration and debris. Clean interior emulsion towers with a soft bristle gun cleaning brush. Clean each Venturi (main carb bore).

Needle Jets & Jet Needles: Clean the needle jets, jet needles, and passageway or tower that needle jet screws into. Clean the emulsion tube (pipe between needle jet and main jet) (Main Jet may screw into emulsion tube). Jet needles are part of the throttle slides. See below…

Throttle Slides: There are several types of throttle slides: Mechanical linkage, vacuum, diaphragm, and cable. Disassembling the jet needle from the slide is not always required for cleaning. If you have vacuum piston type throttle slides (large diameter solid metal slide), avoid cleaning the lubrication from sides and caps. If piston type check cap vents and passageways with air. Clean if necessary and re-lube. If you have rubber vacuum throttle diaphragms, inspect for dry-rot, defects, and tears by gently stretching rubber away from center. Do this until all areas around diaphragm have been inspected. Replace any defective part as described above. Clean carb body areas around diaphragm including air passageways and air jets. Diaphragms have a locator loop or tab fabricated into their sealing edge. Observe this locator upon reassembly. Avoid pinching the diaphragm when reinstalling caps.

Fuel Screws: Fuel screws have sharp tapered ends. Carefully turn one fuel screw in while counting the turns until it seats lightly. Warning: These screws are very easily damaged if over tightened into their seats. Record amount of "turns-in" and remove the fuel screw, spring, washer, and o'ring. The fuel screw is part of the enrichment (choke) circuit...clean passageways as described above. When carbs are assembled, spray low PSI compressed air into diaphragm air vents located at intake side of carbs. Throttle slides should rise, then fall when air is removed. Lightly lube external moving linkages. Reinstall carbs and follow through with carburetor synchronization.

Throttle Cables: Lubricate cables periodically. If cables are disconnected from carbs or removed for replacement, etc . . . remember cable routing and ensure proper reinstallation routing. Avoid bread-tying, sharp bends, and pinching cables. Adjust cables so throttle grip has about 5mm of play or throttle slides or butterfly valves may not open completely (full throttle)(wide full open).

Float Bowls: Inspect float bowls for sediment, gum or varnish, crystallization, and defects. Clean all pipes, tubes, passageways, and embedded jets with cleaners and compressed air. Remove and clean the drain screw and area. Inspect bowl gasket and replace if necessary. Clean and inspect overflow pipes and tubes, look for vertical cracks.

Floats: There are several types of float materials: plastic, brass, black composite, tin, and others. Handle floats carefully. Avoid bending, twisting, denting, or other means of mishandling. Most floats are adjustable by bending a small metal tab near the float axle end. Do not change the float adjuster tab unless tuning fuel service levels. Clean metal floats by soaking or by spraying cleaner and wiping clean. Other material type floats may require replacement if cleaning is necessary. Inspect the needle valve (float valve) and seat. Check needle valve's spring loaded pin. It should depress and return smoothly and without resistance. Check the needle valve's tip for a worn groove. Replace needle valve and seat if either symptom exists. These parts wear together and must be replaced as a set.

Synchronization: This is a fine adjustment performed usually and preferably with the carbs installed and the engine running. The unusual part is performed with gauged wire with the carbs on the work bench. Carburetor synchronizing balances Venturi vacuum at the exhaust side of each carburetor, resulting with smooth idling and optimized performance at all throttle openings. Synchronization is checked using a set of gauges which are either air vacuum type or liquid mercury type. The gauges are connected to vacuum ports on the intake manifolds via nipple tubes or if sealed with screws, sync gauge adapters will be needed. With the engine running at temperature, and with a fan or means of forced convection aimed onto the engine, the carbs fuel screws and idle are adjusted, then the synchronization is adjusted via adjustment screws on the carbs. A reserve fuel tank is recommended for convenience of accessing carbs during this procedure. See gauge instructions and repair manuals for detailed use of synchronization gauges.

Notes: While carbs are apart, record the jet sizes. Look for a very small number imprinted on the body of the jets. Verify that numbers are the same for all jets on models with in-line cylinders. A few transverse-4 models and V-engines, the inner and outer carbs use some different size jets and it's important to not mix them up. If you have dial or veneer calipers, measure and record float heights. Perform measurements with floats just touching needle valves, though not depressing the needle valve rods. Replace fuel and vacuum hoses. Be sure to use fuel rated hose for fuel. Install or replace in-line fuel filters. It's a good time to remove and clean interior petcock fuel filters. Inspect carb manifolds for dry-rotting, inspect all clamps and air ducts. Inspect, clean, lube, and/or replace air filter(s).

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Listen to this man. When I cleaned my carbs I thouht there were gaskets around the towers but it was just dried on cakes of crud, go the extra mile, w'll help you. You'll hit some pitfalls along the way but hey cool is never easty.

Go ahead & remove the carb bodies & soak them or something.
To make it easier I used four plastic divided lunch containers to keep the parts organized & soaked one carb at a time. Most parts only go back one way & you do the same thing four times. It's really quite simple.

newOld_kz1000 wrote:

...'78 kz1000 carbs bank...started to remove the individual carbs from the bracket that holds the 4 carbs together...Think I'll leave 'em be...have not removed the carbs from the brackets...long brass pipe that sticks down from the bottom of the carb body into the float bowl --- what is that brass tube? When I took off the float bowls I noticed it sticking downward, a long brass tube with a small pinhole at the very end where it must be sucking up gas -- for the idle jet? I'm going to stick a small guitar string into that hole to make sure it's not blocked, I believe it's for the idle jet?...what *is* that long brass tube sticking down into the float bowls? It's not the main jet or pilot jet I'm talking about, it's a skinny brass tube with a single hole at the end that sits in the gas in the float bowl -- what is that brass tube there?

Am guessing the thin tube down from carb body into float bowl is likely the enrichner (choke) fuel pickup pipe.

Usually, during typical carb cleaning and refurbishment, the carbs need NOT be separated and detached from the connector plate.

They may be very adquately cleaned with all the carb bodies remaining attached to the plate.

Soak them in carb cleaner, or boil them in vinegar or lemon juice, or whatever.

The vast majority of cleaning will involve the pilot air and fuel passages, pilot jet and main jet, and bleeder pipe, and enrichener (choke) air and fuel passages, overflow circuits, and nooks and crannies inside the float bowls. All accessible enough without separating the carbs.

Certain operations, such as removing and replacing a fuel pipe, will require separation of the particular carbs involved. Because the carbs must be physically separated to remove and then replace the fuel pipe.

The guitar string usually works well to help clean crud from the holes without undesired reaming out the holes.

Good Luck!

Reminder --- do not mix and match the internal carb parts. This especially applies to float valves (needle and seat) which should stay married to each other for life.

Good Luck!

i'm a veg ,so i gotta stay at it till they go back together...an hour or so is all it takes and few cans a spray cleaner....... i use a big peice of card board on my flat bench and either lay everything exact as it comes outta each bowl...and mark each pile 1,2,3,4...or a piece of blue tape to tack the little goodies to the cardboard,as they like to run away......mine are never unracked just bowls and bits removed...don't worry if you miss a passage in cleaning...you'll know if they got clean right away...and the second time i do it i'm fast as a carb guru and twice as cheap.......it's easy and pays off with a clean pulling bike....good luck.....no mixy matchy....

p.s i got a tiny electric screwdriver that makes it way quicker to get all the bowls seated,then- i hand finish em in a sequence......

the bottom line is CLEANLINESS....when ya think they are clean, before you re-assemble, hit em again.....i usually go through about 3 cans carb clean with the air compressor and the cleaning tool from z-1....you know you are doing it right when ya get at least 2 shots of carb clean in the face...:laugh:

OR, you can boil them in lemon juice. I've gone the route of clean, re-assemble, run, clean, re-assemble, run, repeat until they actually are clean, MAYBE.

Get yourself some lemon juice, I used 100% lemon juice, and pull the bowls, jets, needles, seats, and slides out of the carbs. Don't worry about separating the carb bodies from the rack, or the choke plungers/rod. Bring the lemon juice to a boil in a large roaster pan and put the carbs in. Boil them for 15 minutes, roll them around if needed to get all sides of the carbs cleaned. Pull them out, rinse them THOROUGHLY, and blow dry with compressed air (air compressor, not aerosol cans). The bodies of the carbs will start to get chalky, don't worry about that. Once you have them FULLY dried spray them down with PB Blaster and rub that into the outside of the carb bodies, they'll be looking like new in no time.

Or, you can keep burning through cans of carb cleaner. Choice is yours!!!