QuestionI have a 1977 KZ1000 that won't start. Here's a little history to wet the whistle, I bought this bike from a guy that is very reliable, and said that he had cleaned the Carbs before selling to me. This bike was bought new and ridden from 78 to 96, after that, started and ridden once a year until 2000. The only modifications I made were basic, new battery, change oil/oil filter, and cleaned the fuel petcock. Before I bought the bike, the guy had it running on old gas, he then cleaned out the fuel system, put new gas in, and had it started with no problems. I had the bike running for 7 minutes, 3 or 4 times, before dying. After starting and letting bike warm up, I would turn down choke, and the bike would die. So I then adjusted the Idle, and with the choke down the only way the bike would stay Idling is if the Idle adjustment was screwed all the way in, which to me, seems incorrect. I let the bike rest a couple days and when I went back it started right up, unfortunately I had to turn it off quick and run an errand. Within and hour I was back to start up again, the bike would not start up, kicking or electric. It turns over, putts and almost fires, but it acts as though it just doesn't have enough to get going. I made sure that fuel lines were clear and reaching the Carbs. The spark plugs are a little dark but are not disintegrated. It also seems like with all of the attempts to start the bike the battery was low and required a charge. I checked the spark off the plug and it seemed a little orange and may not be getting enough spark do you think this may be a problem? Would new plugs and wires take care of this? Anything you could help me with would be greatly appreciated, thanks.
-Scot
AnswerHi Scot,
Q: I would turn down choke, and the bike would die. So I then adjusted the Idle, and with the choke down the only way the bike would stay Idling is if the Idle adjustment was screwed all the way in, which to me, seems incorrect.
A: This tells me that the gasoline in the float bowls has varnished and is obstructing the pilot circuit. The choke shares circuit passageways with the pilot jet. When the pilot jet/circuit become obstructed by rust particles or varnishing, the choke compensates and allows the engine to start and idle while choke is used. Engine stalss without choke.
Q: I checked the spark off the plug and it seemed a little orange and may not be getting enough spark do you think this may be a problem? Would new plugs and wires take care of this?
A: Orange spark is not good. Try cleaning the spark plugs. If that dosen't return a healthy blue arc, replace the plugs. If the problem persists, check ignition breaker points, gap, condensor, and ignition timing.
Send me an email. I will return several KZ1000 related files, and carburetor tuning, cleaning, and synchronizing files that will assist you. My email is:
mshively1@woh.rr.com
Include the year, make, and model with email.
Respectfully,
Mark Shively
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Engine Doesn't Start, Starting Difficulty:
Starter motor not rotating:
Starter lockout or neutral switch trouble
Starter motor trouble
Battery voltage low
Relays not contacting or operating
Starter button not contacting
Wiring open or shorted
Ignition switch trouble
Engine stop switch trouble
Fuse blown
Starter motor rotating but engine doesn't turn over:
Starter clutch trouble
Engine won't turn over:
Valve seizure
Cylinder, piston seizure
Connecting rod small end seizure
Connecting rod big end seizure
Transmission gear or bearing seizure
Camshaft seizure
Balancer bearing seizure
No fuel flow:
Fuel tap vacuum hose clogged
Fuel tank air vent obstructed
Fuel tap clogged
Fuel line clogged
Float valve clogged
Engine flooded:
Fuel level in carburetor float bowl too high
Float valve worn or stuck open
Starting technique faulty
(When flooded, crank the engine with the throttle fully open to allow more air to reach the engine)
No spark; spark weak:
Battery voltage low
Spark plug dirty, broken, or maladjusted
Spark plug cap or high tension wiring trouble
Spark plug cap not in good contact
Spark plug incorrect
IC ignitor trouble
Neutral, starter lockout, or side stand switch trouble
Pickup coil trouble
Ignition coil trouble
Ignition or engine stop switch shorted
Wiring shorted or open
Fuse blown
Compression low
Spark plug loose
Cylinder head not sufficiently tightened down
Cylinder, piston worn
Piston ring bad (worn, weak, broken, or sticking)
Piston ring/land clearance excessive
Cylinder head gasket damaged
Cylinder head warped
Valve spring broken or weak
Valve not seating properly (valve bent, worn, or carbon accumulation on the seating surface)
Hydraulic lash adjuster damaged (worn, seizure, or spring broken)
Hydraulic lash adjuster oil passage clogged
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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, orings, 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 the Venturi's (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 oring. 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 spray cleaners, if necessary. Replace other type floats if cleaning is necessary. Clean the float axle or pin.
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. It should be the same number for all. 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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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.
