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Author Topic: CB550 Jetting questions with 4in1 exhaust  (Read 1100 times)

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Offline jacksonsk

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CB550 Jetting questions with 4in1 exhaust
« on: April 25, 2020, 06:21:33 PM »
Kept the stock air filter and running a delkavic megaphone 4into1 exhaust. Running lean.
Carbs are stock jets, Was wondering if anyone has input on which jets they are using with their 4in1 with baffle in? I would love to find a place to start. thank you! 8)
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Offline Pielz

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Re: CB550 Jetting questions with 4in1 exhaust
« Reply #1 on: April 25, 2020, 06:55:15 PM »
Delkevic, at least on my 750, specifically said that I didn't need to re-jet. And I didn't!

Sorry I just saw that you said you were running lean. I guess that makes my response pretty unhelpful huh? Lol
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« Last Edit: April 25, 2020, 07:12:15 PM by Pielz »
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Offline jayrdee

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Re: CB550 Jetting questions with 4in1 exhaust
« Reply #2 on: April 25, 2020, 07:13:08 PM »
I just installed a Delkevic 4-1 on my CB750 (and I took the baffle out), went two sizes higher on my main jets, and lowered the needle clip to the middle position. It was originally in the top/lean position.

Was it necessary?  Probably not, but the but dyno feels a difference Lol.
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Offline jc914

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Re: CB550 Jetting questions with 4in1 exhaust
« Reply #3 on: April 29, 2020, 08:45:55 AM »
Try 110 main jets for a start.
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Offline steeldoncb550

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Re: CB550 Jetting questions with 4in1 exhaust
« Reply #4 on: April 29, 2020, 09:34:38 AM »
110’s will be too much for only the exhaust. Start at 100’s.
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Offline Bankerdanny

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Re: CB550 Jetting questions with 4in1 exhaust
« Reply #5 on: April 29, 2020, 09:49:02 AM »
What year and model 550?
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Offline jc914

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Re: CB550 Jetting questions with 4in1 exhaust
« Reply #6 on: April 29, 2020, 10:14:51 AM »
@steeldoncb550,  74-76 (CB550K) stock main jets are#100.  75-77 (CB550F) is #98. 

https://www.sohc4.net/cb550-faq/indexphp/cb500550-carb-specs
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Offline jacksonsk

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Re: CB550 Jetting questions with 4in1 exhaust
« Reply #7 on: April 30, 2020, 05:15:32 PM »
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Offline calj737

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Re: CB550 Jetting questions with 4in1 exhaust
« Reply #8 on: April 30, 2020, 06:28:58 PM »
105s maximum. you should also check the needle clip position. With stock jets, simply moving the needle a clip richer might be easiest and best remedy.
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