Author Topic: CB550 refurb  (Read 149688 times)

Offline Laverdaroo

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Re: CB550 refurb
« Reply #195 on: February 07, 2025, 05:15:30 PM »
I had exactly the same issue with an after market one Jonny but managed to find a good replacement but took two goes to get it right. Same thing, front and back.


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Mornings are the invention of the devil!
1992 VFR750 FN (oldie but goldie) 'Betty'
1977 CB550F (current money pit!!) 'Mejima'
2002 VFR800 VTEC (The Beloved) 'Rose'
1977 CB400F (the last money pit!) 'Chewy'
1998 Ducati 748\853 conversion(sold :()
1980 ish CB750KZ in a billion bits (need to get rid, anybody want one?))

Offline Laverda Dave

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Re: CB550 refurb
« Reply #196 on: February 07, 2025, 05:34:28 PM »
I know it's not needed now you've fixed the problem but Simply Bearings can supply O-Ring chord in various lengths, thickness, colours and choice of material including viton.
Link here:
https://simplybearings.co.uk/shop/Seals-O-Ring-Cord/c19_4549/index.html?selection=VITON+Rubber+O-Ring+Cord
1977 Rickman Honda CR750
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Offline Oddjob

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Re: CB550 refurb
« Reply #197 on: February 07, 2025, 11:28:15 PM »
Not keen on the idea of cord, always a chance it will leak at the join. You can easily measure the existing oring and see if they make one that size. If not you can get some specially made but you need to order 500 as a rule. They’d be cheaper than buying genuine though.
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Offline Johnny4428

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Re: CB550 refurb
« Reply #198 on: February 08, 2025, 08:32:31 AM »
I had exactly the same issue with an after market one Jonny but managed to find a good replacement but took two goes to get it right. Same thing, front and back.


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That’s interesting Roo. I think the ring was thinner at the ends of the sump pan it seemed to just sink right into the groove, unless the groove in the pan was deeper at the ends? More investigation required. If I can get the drain hole threads repaired on the original I will fit it back on at first oil change. It’s in better shape than the replacement I put on. Might purchase an original seal from DS.
1952 Cymoto on Triumph bicycle.
1961 Matchless G3
1974 Honda CB550K1
1978 Honda CB550K3
1999 ST1100 Pan European 50th Anniversary.
1975,1984,1986 Honda C90’s
1973 Honda CB750K3
1977 Honda CB550 (almost)

Offline Laverdaroo

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Re: CB550 refurb
« Reply #199 on: February 08, 2025, 01:36:35 PM »
Same as that Jonny, it appeared thin in the same areas, just as you describe. I shouldn’t thin it’s the pan although I did pass mine over an engineer’s plate just to check. Better than just firing the parts cannon at it


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Mornings are the invention of the devil!
1992 VFR750 FN (oldie but goldie) 'Betty'
1977 CB550F (current money pit!!) 'Mejima'
2002 VFR800 VTEC (The Beloved) 'Rose'
1977 CB400F (the last money pit!) 'Chewy'
1998 Ducati 748\853 conversion(sold :()
1980 ish CB750KZ in a billion bits (need to get rid, anybody want one?))

Offline DomP

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Re: CB550 refurb
« Reply #200 on: February 08, 2025, 07:49:51 PM »
Just a thought, would flatting the sump on some wet n dry to take a bit of material off it be an idea, if all o rings seem to be thinner  then reducing the o ring rebate a touch would solve it.  Non reversible move however.
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Oddjob

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Re: CB550 refurb
« Reply #201 on: February 09, 2025, 12:55:42 AM »
Cheaper and much easier to just buy a genuine oring Dom. I must measure a genuine sump ring and see what dimensions it is, might be available off the shelf from somewhere. I could do with an old one to cut so I can measure it’s length then measure the diameter of a new unused genuine ring to get that figure. Of course I had a few lying around and threw them away when I was cleaning up my collection of sump pans 😯😯
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline DomP

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Re: CB550 refurb
« Reply #202 on: February 09, 2025, 09:19:43 AM »
I thought it might be a bit extreme😄
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Johnny4428

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Re: CB550 refurb
« Reply #203 on: February 09, 2025, 10:46:14 AM »
Just ordered one from DS. £15 odd delivered. Better than a weepy sump!
1952 Cymoto on Triumph bicycle.
1961 Matchless G3
1974 Honda CB550K1
1978 Honda CB550K3
1999 ST1100 Pan European 50th Anniversary.
1975,1984,1986 Honda C90’s
1973 Honda CB750K3
1977 Honda CB550 (almost)

Offline Johnny4428

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Re: CB550 refurb
« Reply #204 on: February 11, 2025, 06:12:24 PM »
Since I had converted to a 500 air filter but retained the 550 air box I have two outlets and one inlet that has nothing attached to them at the moment. Just wondered what would be the best to do with them and indeed what other people have done. There is a condensate drain point on the air filter box and the same on the air plenum. And an inlet on the side of the air filter box for the now defunct carbon capture recycle idea from the breather hose. I was wondering if there was a problem fitting a short bit of hose and connecting the two condensate drains. Has anybody actually had any condensate with the breather bypassed to just vent to atmosphere? I am uncertain and slightly confused what to do. I don’t have any hoses for these, I had a knackered hose from one of these, but nothing reordered till I find out what I need.


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1952 Cymoto on Triumph bicycle.
1961 Matchless G3
1974 Honda CB550K1
1978 Honda CB550K3
1999 ST1100 Pan European 50th Anniversary.
1975,1984,1986 Honda C90’s
1973 Honda CB750K3
1977 Honda CB550 (almost)

Offline DomP

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Re: CB550 refurb
« Reply #205 on: February 11, 2025, 06:34:19 PM »
Interested to know too, Ken suggested to me to do as you have because I was missing so much of the 550 air filter internals.
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Johnny4428

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Re: CB550 refurb
« Reply #206 on: February 11, 2025, 07:40:18 PM »
Don’t want to be sucking unfiltered air such as up through the plenum drain, maybe just needs capped?
1952 Cymoto on Triumph bicycle.
1961 Matchless G3
1974 Honda CB550K1
1978 Honda CB550K3
1999 ST1100 Pan European 50th Anniversary.
1975,1984,1986 Honda C90’s
1973 Honda CB750K3
1977 Honda CB550 (almost)

Offline Bryanj

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Re: CB550 refurb
« Reply #207 on: February 11, 2025, 09:19:51 PM »
I think the original 500 plenum drain was flattened at the end with a slit in it so you could squeeze it open to drain water out

Offline Johnny4428

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Re: CB550 refurb
« Reply #208 on: February 11, 2025, 09:35:47 PM »
I just checked on CMS and still available Bryan.
1952 Cymoto on Triumph bicycle.
1961 Matchless G3
1974 Honda CB550K1
1978 Honda CB550K3
1999 ST1100 Pan European 50th Anniversary.
1975,1984,1986 Honda C90’s
1973 Honda CB750K3
1977 Honda CB550 (almost)

Offline Oddjob

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Re: CB550 refurb
« Reply #209 on: February 11, 2025, 09:39:11 PM »
The plenum drain hose has a one way return valve fitted at the bottom, to empty the hose you squeeze the tube and it lets out any water collected. Saying that, it’s something I’ve never done, they just don’t seem to collect any, or maybe it evaporates during the summer months. As for the hole in the bottom of the air filter box, just leave it, it’s not doing anything and it may help get a little more air into the box if anything obstructs the air duct.

500 filters last longer than 550 ones due to less contamination caused by the recycling system, what a waste of time and money that was, all because of California and it’s anti smog measures.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.