Author Topic: General carb question for cb550 - if you could pick ANY model of carb...  (Read 702 times)

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Offline alacrity

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Hi.
General carb question for a late model cb550.  Let's say you got a bike that didn't have a carb rack, and was also missing the rubber manifolds on the engine side and the airbox rubbers on the other side.

So you need to go source one, and now you have a choice of ANY model rack from any cb500-550 from 1971-78 ... what would you choose and why (let's assume you can work out the small diffs of the airbag rubber fitment etc.

Looking for easiest tunabiity, least hassle, most availability of parts including consumables like o-rings in the rack bits etc. Looking for best power if aftermarket exhaust is used or hotter cam etc.   Without stepping up to cost of a CR rack, what's the "best" carb Honda ever made for these bikes?

Yes, I am hoping for educated opinions here...   Hondaman?  Harisluv? CalJ? SteveO?

Thanks!
I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.

Offline alacrity

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bump
I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.

Offline Deltarider

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You wouldn't care for my opinion would you?
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Offline Bankerdanny

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I would think any carb from the '74-76 K and 75-77F models would be about equal.

Personally I think the later PD series carbs are fine too, the fast idle cam and bar mounted choke is useful. But they are not as easily tuned and are leaner to begin with, so if you are going to make significant mods to the engine they aren't as good an option.
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Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200

Offline carnivorous chicken

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I would think any carb from the '74-76 K and 75-77F models would be about equal.

Personally I think the later PD series carbs are fine too, the fast idle cam and bar mounted choke is useful. But they are not as easily tuned and are leaner to begin with, so if you are going to make significant mods to the engine they aren't as good an option.

Second that. If I remember correctly the earlier ones are easier to sync as well.

Offline alacrity

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I can get any stock air box to work with any cb500/550 carb rack -- the diffs at the interface point are pretty small...  or I can do a clean pod setup and make that work.

I have pd46a but I thought maybe an earlier setup (before Honda really cared much about emission or consumption) would give me more latitude.
I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.

Offline Deltarider

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I have pd46a but I thought maybe an earlier setup (before Honda really cared much about emission or consumption) would give me more latitude.
Oh... but that's for sure. Back then the K3s with PDs were often critisised for being too lean. IMO the oldstyle Keihins are much easier to work on. Slow jets in the PD have a tendency to become (partially) clogged.
Quote
the fast idle cam and bar mounted choke is useful.
Personally I think it offers nothing and I regret Honda plastered the later models 500/550 with cables and tubes all over the bike.
« Last Edit: July 13, 2016, 07:14:36 AM by Deltarider »
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