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Author Topic: From Pods to factory air box big change in plugs  (Read 2653 times)

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Offline dhall57

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From Pods to factory air box big change in plugs
« on: July 16, 2011, 01:18:40 PM »
#2,3, and 4 cylinder plugs are almost identical so I just took pic of cyl 1 plugs. One on left is a Champion plug and this is what was in my 70 KO when I bought in May and been running these until a few days ago. Brownish color looks ok. Carbs are not the original KO's they are the 657b type with 105 and 40 jets and air screws are 1 turn out. Still running factory HM300 pipes, but with pod filters. 2 days ago I got rid of the pods and put a factory air box back on it with new tubes, and housing seal and a K&N filter and new NGK D8EA plugs, but no other changes. One on right is one of those plugs with only about 200 miles on it. I took them out expecting for them to be a nice brown color, but was surprised that they were running so lean. Did the factory air box and K&N cause this lean condition? What do I need to do to get rid of this lean running. Go back to pods?
thanks
dhall
« Last Edit: July 16, 2011, 04:10:01 PM by dhall57 »
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1976 CB750K6
1977 GL1000
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Offline crackerbat

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Re: From Pods to factory air box big change in plugs
« Reply #1 on: July 16, 2011, 07:37:43 PM »
that seems... backwards to me.
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Offline Spanner 1

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Re: From Pods to factory air box big change in plugs
« Reply #2 on: July 16, 2011, 08:28:06 PM »
Stock Main Jets on a K0/K1 is 120, not 105.  ;)
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Offline ekpent

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Re: From Pods to factory air box big change in plugs
« Reply #3 on: July 16, 2011, 08:32:49 PM »
Quote from: Spanner 1 on July 16, 2011, 08:28:06 PM
Stock Main Jets on a K0/K1 is 120, not 105.  ;)
Yep that is correct-better jet it up.
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Offline dhall57

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Re: From Pods to factory air box big change in plugs
« Reply #4 on: July 17, 2011, 02:34:29 AM »
Quote from: ekpent on July 16, 2011, 08:32:49 PM
Quote from: Spanner 1 on July 16, 2011, 08:28:06 PM
Stock Main Jets on a K0/K1 is 120, not 105.  ;)
Yep that is correct-better jet it up.
So I need to run 120's even though my carbs aren't the factory KO carbs, there the later #657b carbs that shows to take 105 jets.
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1970 CB750KO
1971 CB500KO-project bike
1973 CB350G- project bike
1974 CB750K4-project bike
1974 CB750K4
1976 CB750K6
1977 GL1000
1997 Harley Wideglide

Offline Retro Rocket

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Re: From Pods to factory air box big change in plugs
« Reply #5 on: July 17, 2011, 04:05:47 AM »
Quote from: dhall57 on July 17, 2011, 02:34:29 AM
Quote from: ekpent on July 16, 2011, 08:32:49 PM
Quote from: Spanner 1 on July 16, 2011, 08:28:06 PM
Stock Main Jets on a K0/K1 is 120, not 105.  ;)
Yep that is correct-better jet it up.
So I need to run 120's even though my carbs aren't the factory KO carbs, there the later #657b carbs that shows to take 105 jets.

If i am correct, the K0 and K1 had bigger cam and better breathing pipes requiring bigger jets, also there was no pollution bull#$%* early on so they also ran a little richer.... ;)
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Offline bwaller

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Re: From Pods to factory air box big change in plugs
« Reply #6 on: July 17, 2011, 04:10:30 AM »
Suit the jetting to the model engine, not so much the model carbs.
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Offline fire113

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Re: From Pods to factory air box big change in plugs
« Reply #7 on: July 17, 2011, 05:14:55 AM »
Quote from: dhall57 on July 17, 2011, 02:34:29 AM
Quote from: ekpent on July 16, 2011, 08:32:49 PM
Quote from: Spanner 1 on July 16, 2011, 08:28:06 PM
Stock Main Jets on a K0/K1 is 120, not 105.  ;)
Yep that is correct-better jet it up.
So I need to run 120's even though my carbs aren't the factory KO carbs, there the later #657b carbs that shows to take 105 jets.

...with the K&N air filter You need bigger main jets then the stock jetting.

In the next days I will try ~140 main jets with HM 300, original air box and the K&N air filter element then I can tell You.
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Offline dhall57

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Re: From Pods to factory air box big change in plugs
« Reply #8 on: July 17, 2011, 06:39:52 AM »
Where is they best place to get high quality carb jets, not some cheap aftermarket replacement.
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1970 CB750KO
1971 CB500KO-project bike
1973 CB350G- project bike
1974 CB750K4-project bike
1974 CB750K4
1976 CB750K6
1977 GL1000
1997 Harley Wideglide

Offline Spanner 1

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Re: From Pods to factory air box big change in plugs
« Reply #9 on: July 17, 2011, 07:09:08 AM »
 I've had good success with jets from Z1 Ent. Don't know who makes them but the reports I'xe seen seem to be more about jet needles not being the correct profile when aftermarket, rather than any probs with actual jets.
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If your sure it's a carb problem; it's ignition,
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Offline david 750f

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Re: From Pods to factory air box big change in plugs
« Reply #10 on: July 17, 2011, 07:52:14 AM »
Honda still sells new main jets.
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Offline Flying J

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Re: From Pods to factory air box big change in plugs
« Reply #11 on: July 17, 2011, 08:37:54 AM »
Jets r us sells both. They have genuine replacement and then oem equivalent at about half the price.

http://www.jetsrus.com/a_jet_kit_street/honda_750_CB750_1969-1971.html
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