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One cylinder not cutting out
- KZCool
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1976 KZ750 hardtail
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- Patton
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Possible erratic spark, perhaps from a bad plug wire leaking voltage to the engine head.KZCool wrote: So I recently took my engine out of my 76 kz750 twin due to my kickstart failing, and after fixing that problem and getting it back in only one of my cylinders is firing consistantly. The other will pop and fire and cut out and back fire and all that jazz. If I open the throttle a little it seems to not be nearly as bad. Ive taken the carbs off cleaned them, checked the timing, recently checked and regapped the valves, checked the voltage comming off my dyna S ignition and it was fine, and the only thing I can come up with is that the coil is bad. It's a wasted spark system though and the other cylinder fires just fine. Anyone know if it is possible that the coil could be bad? Its the original coil too.
Could remove both plugs, tape them together (or hold both against the engine head) and assess spark quality while spinning the engine over.
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1973 Z1
KZ900 LTD
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- MFolks
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1982 GPZ1100 B2
General Dynamics/Convair 1983-1993
GLCM BGM-109 Tomahawk, AGM-129A Advanced Cruise Missile (ACM)
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- KZCool
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MFolks wrote: I'd replace both sparkplug caps as they contain a 5000 ohm resistor that over time can go bad, making for erratic spark at the plug. Tried another brand of sparkplug? I've found that some of the US made NGK's are not as good as the ones made in Japan.
Thanks a ton for the advice. sure enough I checked the resistance of one of the caps and it was 5 something kilo-ohms and the other was infinite, just ordered some new ones from Z1 so I should be riding in 2 days. Thanks again.
1976 KZ750 hardtail
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- MFolks
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These 4 strokes need but four things to run:
1.Compression
2.Clean air
3.Fuel
4.Spark
If any of the above are not there, the engine will not run.
1982 GPZ1100 B2
General Dynamics/Convair 1983-1993
GLCM BGM-109 Tomahawk, AGM-129A Advanced Cruise Missile (ACM)
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- KZCool
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1976 KZ750 hardtail
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- baldy110
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- Kapahulu
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Yesterday my dog ate one of my plug wires. I replaced the wire (dyna coil) and the bike was running cruddy at idle. I thought something had clogged the pilot jets and I cleaned the carbs. That didn't fix the problem and then I realized the connection from the plug wire to the coil was not 100%. With that fixed, the KZ runs like a champ - even better than before with the freshly cleaned idle circuits.
1978 KZ1000, 1976 KZ900, 1975 H2, 1973 H1, 1973 H2, 1978 RD400, 1977 RD400, 1974 RD350
2strokeworld.com
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- KZCool
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1976 KZ750 hardtail
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- Patton
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Patton wrote: ...Could remove both plugs, tape them together (or hold both against the engine head) and assess spark quality while spinning the engine over....
Do both plugs show fat blue sparks?
Good Fortune!
1973 Z1
KZ900 LTD
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- Patton
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Good Fortune!
1973 Z1
KZ900 LTD
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