Cylinder 2&3 not firing
- darikfrye91
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Cylinder 2&3 not firing
09 Aug 2016 18:58
Hello so I have a 1982 KZ550 A3. And I cleaned the carbs and went to sync them and noticed that the gauge said zero for cylinder 2 and 3. The gauge has been tested and works. I also noticed whereas cylinder 1&4 exhausts were hot to the touch, 2&3 I was able to grab ahold of. I checked for spark and tested the coils and they were within spec and the spark plug sparked when I was held it to the head and cranked it over. I also checked the pickup coils and they were good too. What am I missing here? Any and all help would be great! Thanks!
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- SWest
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Re: Cylinder 2&3 not firing
09 Aug 2016 19:32
Did you bench sync the carbs?
Steve
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
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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- missionkz
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Re: Cylinder 2&3 not firing
09 Aug 2016 20:18
It would be a coincidence, but two leaking exhaust valves could do it.
I'd still be checking carbs
I'd still be checking carbs
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
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- DoctoRot
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Re: Cylinder 2&3 not firing
09 Aug 2016 20:22
have you checked compression? even if 2&3 are not firing they will still create vacuum.
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- Patton
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Re: Cylinder 2&3 not firing
10 Aug 2016 00:20
Did cyl 2/3 stay cold before the carb cleaning?
Good Fortune!
Good Fortune!
1973 Z1
KZ900 LTD
KZ900 LTD
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- wrenchmonkey
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Re: Cylinder 2&3 not firing
10 Aug 2016 07:14
Ditto what Patton asked?
Assumptions we have to make:
it sounds like you've got spark on cylinders 2 & 3 - Fire
Just cleaned carbs & knew enough to synch them - Fuel
This leaves the only other thing missing as - Compression
Have you checked your valve gaps recently? An '82 550 is pretty easy to check - just checking, not adjusting is a job in under an hour.
Any history on your bike would be very useful here to help diagnose further:
- Is the bike your old, trusted, daily rider or a just purchased and unknown?
- Did the engine ever run in your presence?
- What if anything has been done recently/prior to the carb cleaning?
- How many miles are on the odometer?
I've (recently even) had a brand new coil pack go bad. It works initially but fails within about 5 minutes but it's apparently a rarer thing so with all else we know, it seems you are only missing compression on cylinders 2 and 3 which would be most likely explanation of valves are staying open due to no valve gap. You might find cylinder 1 and 4 are on the edge of needing adjusting too and just lucky that they are still firing as well.
Assumptions we have to make:
it sounds like you've got spark on cylinders 2 & 3 - Fire
Just cleaned carbs & knew enough to synch them - Fuel
This leaves the only other thing missing as - Compression
Have you checked your valve gaps recently? An '82 550 is pretty easy to check - just checking, not adjusting is a job in under an hour.
Any history on your bike would be very useful here to help diagnose further:
- Is the bike your old, trusted, daily rider or a just purchased and unknown?
- Did the engine ever run in your presence?
- What if anything has been done recently/prior to the carb cleaning?
- How many miles are on the odometer?
I've (recently even) had a brand new coil pack go bad. It works initially but fails within about 5 minutes but it's apparently a rarer thing so with all else we know, it seems you are only missing compression on cylinders 2 and 3 which would be most likely explanation of valves are staying open due to no valve gap. You might find cylinder 1 and 4 are on the edge of needing adjusting too and just lucky that they are still firing as well.
The following user(s) said Thank You: GatlinM
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