QuestionI have a 78 kawasaki kx 650 that has been sitting for a couple years that was givin to me and im trying to get it running i drained the gass put new in took apart the carborators cleaned them and mechanically syncd them with a piece of wire it will start right up but i cant get it to idle low and if i take off the jumper cables which i use to start it then it wont run like it did with them on (this is a new battery) it will still run with them off but it will just shut off randomly for no reason i hear some clicking noise when its running and it seems to change the idle speed i dont know what else to tell you im gonna test the altenator tommorow with a voltometer maybe you can give me a little more info thanks
AnswerHi Brad,
I suspect more than one problem going on.
The carburetors may need more thoroughly cleaned, tuned, and synchronized.
The charging system needs attention. Perform an output test and test the regulator/rectifier.
Correction... I would send tech files to your email, but there is no email address with your question as requested.
Respectfully,
Mark Shively
Bad Gas
By Mark Shively
Gasoline goes bad with time and in as little as 3-4 weeks. This effect is known as varnishing. Jets and passageways within carbs become obstructed when varnishing occurs.
Liquid gasoline changes chemically into a gel like substance. Advanced stages of varnishing results with the solid gel changing into a crystal powder substance. Interior carb surfaces are etched in the process and may require carb replacement.
The choke and pilot circuits with most motorcycle carburetors share passageways. When pilot jets become obstructed, the choke circuit compensates and allows engine to start and idle with choke, but stalls without choke.
See carb cleaning information below. See microfiche parts, check parts prices, and order repair manuals here: www.bikebandit.com
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 have effects on 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 verneer 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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Kawasaki liked to hide the regulator/rectifier under the battery holder on those bikes. That way, the connections could be assured of getting hosed with acid.
Here's what ya do. Charge the battery and then start the engine. Rev engine to around 3500. Check the DC voltage at the battery. If it's around 14 volts, you're good. If it's just shy of that, hit the rear brake to get the light to come on. If the voltage drops, you're definitely not charging.
Find the reg/rec and look for the connector coming from it. Pop it apart and check for green (corroded) or burnt wires and pins, especially the 3 yellow wires going into it. Stock Kaw reg/rec suck ass and will die at the drop of a hat. Go to www.electrosport.com and buy a replacement. They are cheaper and better than stock. Do this as a precaution.
The other part that screws up on Kaw's is the alternator stator. The windings break down and fry. Pull the sprocket cover and find the 3 yellow wires that come out of the alternator cover. Be careful as these will be petrified, probably burned and very brittle. Carefully disconnect them and check the resistance between each yellow wire and ground. They should be effectively open, not shorted. Then check the resistance between each combo of yellow wires. They should be about the same. That is, very low resistance. Not open. If any of the above is hosed up, yank the alternator cover, buy a gasket and go to Electro Sport again for a better than stock replacement. If you are going to take the bike's reliability seriously, replace both the alt and reg/rec as a precaution. Yeah, it'll be probably 3 bills, but it beats tow charges from Podunk.
Don't buy used parts or you'll be doing this again very soon. This was probably the weakest point of all the KZ 4's, and some of the early ZX's, too. Now you know where those Lucas engineers went after Triumph finally died!
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1977-78 Kawasaki KZ1000 Charging System Troubleshooter
1.) Battery Test (ignition off): Meter Scale: 20V DC, Meter Connections: Red test lead to Positive battery terminal, Black test lead to Negative battery terminal, Specifications: 12V min. No more than 1V drop, If up to spec proceed; if below spec, replace battery and retest.
2.) Battery Test (ignition on) (lights on): Meter Scale: 20V DC, Meter Connections: Red test lead to Positive battery terminal, Black test lead to Negative battery terminal, Specifications: 12V min. No more than 1V drop; If up to spec proceed, if below spec charge or replace battery and retest.
3.) Charging System Test: Meter Scale: 20V DC, Meter Connections: Red test lead to Positive battery terminal, Black test lead to Negative battery terminal, Specifications: 13.6V @ 4000 RPM; If above or below spec proceed to next test, if up to spec-charging system is OK.
4.) Alternator Test: Meter Scale: 120V AC, Meter Connections: Disconnect alternator output leads. Check AC output between all three alternator leads @4000 RPM, Specifications: 62V @ 4000 RPM; If up to spec proceed, if low-replace dyno armature and retest.
5.) Rectifier Test: Meter Scale: R x 1 Ohms, Meter Connections: (Disconnect Rectifier) (1) Connect Black test lead to ground wire from rectifier. With Red meter lead, check each Yellow rectifier lead for resistance. (2) Connect Red test lead to ground wire from rectifier. With Black meter lead, check each Yellow rectifier lead for resistance. Specifications: Resistance in one direction, very little resistance when test leads are reversed (check service manual for ohm specs). If good proceed, if bad replace rectifier and retest.
6.) Regulator Test: Meter Scale: 12 Amp, Meter Connections: Connect meter in series with battery. Connect Black meter lead to ground, and Red meter lead to Negative terminal of battery. Kick start engine, and recheck meter reading @ 4000 RPM. CAUTION! Do not use electric starter. Specifications: 5.8A @ 4000 RPM; If up to spec proceed, if high or low-replace replace regulator and retest.
7.) Unregulated System Test: Meter Scale: 12 Amp, Meter Connections: (Disconnect regulator from system) Connect meter in series with battery. Connect Black meter lead to ground, and Red meter lead to Negative terminal of battery. Kick start engine, and recheck meter reading @ 4000 RPM. CAUTION! Do not use electric starter. Specifications: 9.5A @ 4000 RPM; If good, test complete. If bad, go back to #1 – Start over.
