Black Plugs and Cool Pipe

  • 650Dude
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Black Plugs and Cool Pipe

04 Jan 2018 15:37
#776925
Running rich. Black plugs and a pipe that only stays warm when I change or clean the spark plugs. Cylinder or pipe 1 is NEVER as hot as the other pipes. Im thinking carb issue?
1977 Kawasaki KZ650B
1977 Kawasaki KZ750 Twin

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  • SWest
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Re: Black Plugs and Cool Pipe

04 Jan 2018 18:05
#776930
Pic of the plugs?
Steve
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229

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Re: Black Plugs and Cool Pipe

04 Jan 2018 18:08
#776931
SWest wrote: Pic of the plugs?
Steve

The bike has been in the garage a while. I can assure you the plugs are black with soot, not oil, and the exhaust is ridiculously black. Its running entirely too rich. I was just asking the question "would it be the carbs that is causing one of the pipes not to get hot"
1977 Kawasaki KZ650B
1977 Kawasaki KZ750 Twin

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Re: Black Plugs and Cool Pipe

04 Jan 2018 18:16
#776933
Could be a lot of things, coils, wires, timing, valves, etc. Stock carbs, modifications?
Steve
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229

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Re: Black Plugs and Cool Pipe

04 Jan 2018 18:18
#776934
SWest wrote: Could be a lot of things, coils, wires, timing, valves, etc. Stock carbs, modifications?
Steve

no mods. coil is fine, timing is fine stock carbs but 4 into 1 jets that were rejetted by the PO.
1977 Kawasaki KZ650B
1977 Kawasaki KZ750 Twin

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  • ajsfirehawk
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Re: Black Plugs and Cool Pipe

04 Jan 2018 18:29 - 04 Jan 2018 18:31
#776937
Your subject title suggests you aren't getting fire. It may be carbs and jetting but I'd check the coils first. Voltage on the coils (there are two and you used the singular "coil" in the previous post) should be 12V or more with the ignition key in the ON position. Check the coils themselves, meaning buzz out the primaries and secondary windings to verify they have the proper resistance values. Hard for me to imagine upsizing the jets a few sizes would swamp the cylinders so much they wouldn't fire. If your problem only exists on cylinder #1 take a hard look and buzz out that plug wire. Points or electronic ignition?
79 KZ650 SR
80 KZ1000 Z1 Classic
83 KZ1100 LTD
Z900RS
23 Mach 1
Last edit: 04 Jan 2018 18:31 by ajsfirehawk.

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Re: Black Plugs and Cool Pipe

04 Jan 2018 18:38
#776938
ajsfirehawk wrote: Your subject title suggests you aren't getting fire. It may be carbs and jetting but I'd check the coils first. Voltage on the coils (there are two and you used the singular "coil" in the previous post) should be 12V or more with the ignition key in the ON position. Check the coils themselves, meaning buzz out the primaries and secondary windings to verify they have the proper resistance values. Hard for me to imagine upsizing the jets a few sizes would swamp the cylinders so much they wouldn't fire. If your problem only exists on cylinder #1 take a hard look and buzz out that plug wire. Points or electronic ignition?

Coils points and all that were done in a tuneup. the stock jetting is 100 main 40 pilot. I just found out the PO put in 42 pilot to compensate for the aftermarket 4 into 1 exhaust. He should NOT have adjusted the pilot. He should have adjusted the main. Im bumping the main up to 110 and taking the pilot back to stock
1977 Kawasaki KZ650B
1977 Kawasaki KZ750 Twin

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