Author Topic: Carbs  (Read 623 times)

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Offline yellowjacket

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Carbs
« on: November 03, 2015, 09:33:34 AM »
Just purchased a 1978 cb550.  It has sat for years. It is fairly complete.  The bike does not have any carbs on it right now.  The guy who I bought it from had purchased a set of carbs off a 1974 cb550 and gave them to me as part of the deal.  Will these carbs work on the bike? 

Offline DaveBarbier

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Re: Carbs
« Reply #1 on: November 03, 2015, 10:07:20 AM »
As far as I know they should fit. But you won't be able to use the factory settings regarding jet sized and needle positions. Others will chime in to confirm or deny my assertion.

I have a spare rack of PD46c carbs (the ones for your bike) that I'd sell you cheap if you want. I was having troubles with them but figured out it was actually the pilot jets that were the culprit and not the carbs. They're not complete (missing some jets).

Honestly you'll probably be fine with your current carbs after you get them tuned but if you're interested, let me know.

Offline jonda500

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Re: Carbs
« Reply #2 on: November 03, 2015, 03:08:30 PM »
If your '78 still has 4 into 4 exhausts your '74 carbs should work without changing the jets or settings provided that you have an original air chamber & filter. Changes to the exhaust/air intake will mean retuning the carbs is required.
John
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A starter clutch thread:
http://forums.sohc4.net/index.php/topic,122084.0.html
1972 CB500K1 original 4 owner bike
1972 CB500K1 returned to complete/original condition
1975 CB550F built from parts - project thread:
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197? CB500/550 constructing from left over parts
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Offline carnivorous chicken

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Re: Carbs
« Reply #3 on: November 03, 2015, 06:10:54 PM »
You also might not have inlets for your carb synchronization on the 1978 manifold but will need them with 1974 carbs. 1974 manifolds can be had for cheap on Ebay... $25 or so.

Offline eoddom

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Re: Carbs
« Reply #4 on: November 03, 2015, 06:24:31 PM »
Or I'll sell ya a set of carbs that need a cleaning and rebuild for it