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primary main vs secondary main
- moke
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01 Nov 2011 19:25 #486537
by moke
It's not what you ride it's that you ride!
1980 Kawasaki KZ250 LTD (current project)
1978 Honda CB400
1987 Honda Elite 50 (speed project)
primary main vs secondary main was created by moke
If i understand right the primary main is pretty much a slow jet correct? and then the secondary main is the actual main jet? Is upjetting the primary main ever required? Feel free to school the newbie
It's not what you ride it's that you ride!
1980 Kawasaki KZ250 LTD (current project)
1978 Honda CB400
1987 Honda Elite 50 (speed project)
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- 750steve
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01 Nov 2011 19:30 - 01 Nov 2011 19:32 #486539
by 750steve
07 ZX6R Race Bike
1977 Z750 B2 Twin
1976 Z650 B1
Replied by 750steve on topic primary main vs secondary main
I'm still learning too but i believe what you say is indeed correct
I'm sure it depends on many factors wheather it needs upped or not, airflow, weather & barometric pressure will all play a factor & thats just some variables
I'm sure it depends on many factors wheather it needs upped or not, airflow, weather & barometric pressure will all play a factor & thats just some variables
07 ZX6R Race Bike
1977 Z750 B2 Twin
1976 Z650 B1
Last edit: 01 Nov 2011 19:32 by 750steve.
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- loudhvx
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01 Nov 2011 20:43 - 01 Nov 2011 21:04 #486557
by loudhvx
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
Replied by loudhvx on topic primary main vs secondary main
I also believe that is correct... the secondary is basically the main. But I'm not sure if it's standard on all carbs with dual mains.
The primary is sort of in-between the idle jet and the secondary main. So there are actually 3 circuits to adjust and clean (at least 3).
And yes, in some instances you may have to change the primary. I had to use larger primary and secondary on some KZ400 carbs to run pods and open exhaust. However getting the exact right jetting requires a lot of time and testing for CV carbs using multiple mains, and changing one will affect what the other will need to be.
The primary is sort of in-between the idle jet and the secondary main. So there are actually 3 circuits to adjust and clean (at least 3).
And yes, in some instances you may have to change the primary. I had to use larger primary and secondary on some KZ400 carbs to run pods and open exhaust. However getting the exact right jetting requires a lot of time and testing for CV carbs using multiple mains, and changing one will affect what the other will need to be.
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
Last edit: 01 Nov 2011 21:04 by loudhvx.
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- JR
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01 Nov 2011 21:49 #486572
by JR
1980 kz750E1, Delkevic exhaust
Replied by JR on topic primary main vs secondary main
I increased the size of both primary and secondary when I had pods on the 750/4
1980 kz750E1, Delkevic exhaust
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- moke
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02 Nov 2011 00:36 #486644
by moke
It's not what you ride it's that you ride!
1980 Kawasaki KZ250 LTD (current project)
1978 Honda CB400
1987 Honda Elite 50 (speed project)
Replied by moke on topic primary main vs secondary main
thats exactly what im attempting with this is pods err pod single cyl. But for upjetting would the same +2 sizes per mod albeit exhaust pods or both also apply to the primary along with the secondary?
It's not what you ride it's that you ride!
1980 Kawasaki KZ250 LTD (current project)
1978 Honda CB400
1987 Honda Elite 50 (speed project)
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- JR
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02 Nov 2011 20:56 #486733
by JR
Experiment, observe, deduce.
1980 kz750E1, Delkevic exhaust
Replied by JR on topic primary main vs secondary main
moke wrote: thats exactly what im attempting with this is pods err pod single cyl. But for upjetting would the same +2 sizes per mod albeit exhaust pods or both also apply to the primary along with the secondary?
Experiment, observe, deduce.
1980 kz750E1, Delkevic exhaust
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02 Nov 2011 21:34 #486739
by loudhvx
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
Replied by loudhvx on topic primary main vs secondary main
Start with changes in the 10% range for the secondary main, and maybe 5% on the primary and pilot.
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
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