Author Topic: 75 cb550 jetting?  (Read 1951 times)

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Offline 550Z

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75 cb550 jetting?
« on: July 11, 2012, 01:43:52 AM »
 I have a 75 cb550 that has pods and headers and is running 100 mains and 38 idle and it runs like #$%*.... im planning on putting a mac 4 into 1 on it with pods. What would be the best jet size for it?

Offline Dimitri13

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Re: 75 cb550 jetting?
« Reply #1 on: July 11, 2012, 02:19:15 AM »
Start off by not using the pods. Put the MAC 4-1 on it with a baffle, stock jet size 100 and 38, and it'll run cherry.

Offline sinister902

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Re: 75 cb550 jetting?
« Reply #2 on: July 11, 2012, 07:22:00 AM »
with the pods, you will probably need 105 or 110 mains. I'm running 115's and they are too rich with pods and exhaust upgrades. You're also probably going to have to move your needle clip down one notch and fiddle with the mixture screw.

Offline lucky

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Re: 75 cb550 jetting?
« Reply #3 on: July 11, 2012, 01:17:57 PM »
Yes I would use the #110 main jets.
#40 idle jet with pods.

Do not move the needle clip at this time.

If that combo does not get good results, then go back to stock main jet and raise the needle by lowing the clip one notch.

Raising the needle richens up the range from 1/4 throttle to full throttle.

Offline db22

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Re: 75 cb550 jetting?
« Reply #4 on: July 11, 2012, 07:19:01 PM »
Depends on the pods. I've tried Emgo metal mesh ones, and UNI foam pods. Currently using the UNIs with no oil, with 102 mains and 40 pilot jets, mixture screws out one-half turn (PD carbs). With Emgo metal pods, I used 105 mains, 40 pilots, 1.5 turns.. Bike is a '75 CB550K, with '77 carbs, MAC 4->1 header, baffle in the muffler.
1975 CB550K (rider)
1975 CB550K (shaping up, slowly)
I may be goin' to hell in a bucket, but at least I'm enjoyin' the ride. . .

Offline luap

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Re: 75 cb550 jetting?
« Reply #5 on: July 11, 2012, 09:44:44 PM »
for me mac 4into1 modified slight baffle 110 mains 40 idle needle clip 4th, to rich at idle bog off line going back to 38 an make a different baffle mid range an top end good 75 550
73 500 with 550 motor with 022a carbs 110 main 3rd positon mac 4int1 modified with baffle 40 idles- rips
both running uni pk3 or pk22 pods
other 550  4into2 drag pipes open 110 main 3rd clip 38 idles- ripped
different one K&N style filter(sucks) 110 main 2nd clip 38 idles 4into4 drag pipes open
couple other but in az with pods an modified pipes 110 main seems to be a good starting point
A/F screw all 1.25-2 turns out
BUT each one of those bikes have been sold outside of AZ an I get the phone call WTF the bike rides like crap AFTER ive told them they will need to rejet. 
 
75-550 ffsc sold, 78-550 diamonte sold, 125s grasshopper sold, 76-550 puma sold, 78-550 tracker sold, 74-550 verde diablo Sold, 74-550 Noemani finished trying to sell. 72 500 hartail in the works
www.cb-town.com
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Offline Gentlemanjim

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Re: 75 cb550 jetting?
« Reply #6 on: July 11, 2012, 09:50:24 PM »
My CB650 (esentially the same engine) has 120 mains with pods and MAC 4 to 1 and runs perfect

Offline Dimitri13

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Re: 75 cb550 jetting?
« Reply #7 on: July 11, 2012, 10:18:11 PM »
My CB650 (esentially the same engine)

Except a different top end.

Offline TwoTired

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Re: 75 cb550 jetting?
« Reply #8 on: July 11, 2012, 11:06:38 PM »
"PODs" is not a specification.  It is a style. 

How does one re-jet simply because of style?
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline 550Z

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Re: 75 cb550 jetting?
« Reply #9 on: July 12, 2012, 02:21:10 AM »
alright ill look into the new jets