Author Topic: Doms CB550F1 project  (Read 240968 times)

Offline DomP

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Re: Doms CB550F1 project
« Reply #735 on: May 21, 2025, 03:27:12 PM »
Baking it with an electric heater seems to have done the trick, I'm really paranoid about flatting it all back though😳  CCR recommend 1500,2000,2500,3000 then a polish, any paint guys care to weigh in on this?
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Laverdaroo

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Re: Doms CB550F1 project
« Reply #736 on: May 21, 2025, 04:39:46 PM »
I’d go straight to the higher numbered w&d Dom for fear of shredding it. Plenty of water with a squirt of fairy liquid in it and it should rub up well if you’re happy on the set of the paint!
I thought the UV would have done it but chuffed you’re getting there buddy.


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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: Doms CB550F1 project
« Reply #737 on: May 21, 2025, 04:50:10 PM »
Yeah its definitely getting there, just splashing the cash on heating the workshop up🤣

Do these carb adjusters look at bit far out?  Most photos I see they only show a few threads.  I think I'm going to get them off and revisit the whole carb thing while the tanks hardening up.
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Laverdaroo

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Re: Doms CB550F1 project
« Reply #738 on: May 21, 2025, 04:52:36 PM »
Yeah its definitely getting there, just splashing the cash on heating the workshop up

Do these carb adjusters look at bit far out?  Most photos I see they only show a few threads.  I think I'm going to get them off and revisit the whole carb thing while the tanks hardening up.
Yeah, a bit I think by happy to be corrected, it’s not a huge job to sort though bud, better to be safe than sorry. I’ve both the 400 and the 550 to do once they see the light of day again. Booo! think yerself lucky


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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: Doms CB550F1 project
« Reply #739 on: May 21, 2025, 04:58:02 PM »
I need to just knuckle down and get it on the road
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Laverda Dave

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Re: Doms CB550F1 project
« Reply #740 on: May 21, 2025, 10:18:20 PM »
Yeah its definitely getting there, just splashing the cash on heating the workshop up🤣

Do these carb adjusters look at bit far out?  Most photos I see they only show a few threads.  I think I'm going to get them off and revisit the whole carb thing while the tanks hardening up.

I had a similar issue with the 400/4 carbs Dom. I couldn't understand why so took the carbs off to check. Turned out I had the choke fast idle screw set out too far (the screw that is part of a hex head adjuster and is offset to the hex so as you turn the screw to adjust it it moves concentrically against the carb fast idle lever which is a ramp basically and it in turn raises the carb slides to increase the revs). This only operates when you have the choke on BUT if it is set incorrectly with no clearance when the choke is off the slides will not close properly and you end up winding out those carb adjusting screws as per your photo in an attempt to drop the revs but you won't succeed because the cold start lever has no clearance!
That's how it works on the 400/4 Carbs anyway, it may be completely different on the 550!
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'The Flying Banana'
1982 Laverda 120 Jota
2020 Royal Enfield Interceptor 650
1990 Honda VFR400R NC30

Offline Laverdaroo

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Re: Doms CB550F1 project
« Reply #741 on: May 21, 2025, 10:28:17 PM »
I’d forgotten about that Dave, that’s what the issue was when I originally started the 400, completely forgotten about doing exactly the same thing. It suddenly clicked and I did as you just described. I wonder how many people have had just that issue.

It’s 18 months or so since the 550 was started due to fear of glazing the bores and worked on the mudguards, tank etc. I couldn’t run it as I didn’t have a seat anyway until early this year so until I could, starting wasn’t a priority.

Again, can’t remember what I did to get it running nicely, too much crap has occurred since then and my ‘head’s a shed) at the min. The dusty filing cabinet of a memory can’t dig that one out at the min..


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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: Doms CB550F1 project
« Reply #742 on: May 21, 2025, 10:40:32 PM »
I think I follow that Dave.  To be honest, getting that part where the throttle comes to a stop on the off set hex you are referring to has been  a bit troublesome.  There are some measurements in the Honda manual that are so sketchy I still can't work out where they are measuring from.
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline DomP

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Re: Doms CB550F1 project
« Reply #743 on: May 22, 2025, 08:18:45 PM »
Definitely 2nd from top not bottom for 069a carbs? Cb550f
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Oddjob

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Re: Doms CB550F1 project
« Reply #744 on: May 22, 2025, 09:13:42 PM »
Yep, 2nd down, on needles marked 273004.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline DomP

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Re: Doms CB550F1 project
« Reply #745 on: May 22, 2025, 10:39:55 PM »
Thanks Ken, can you link me to or remind me of the most reliable bench sync that will leave me with the correct amount of travel on the bell crank and idle screw?
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Oddjob

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Re: Doms CB550F1 project
« Reply #746 on: May 23, 2025, 01:16:04 AM »
There are a few different ways and I’m not saying one is better than the other but I’ve always used this way myself and it seems to work for me.

Wind the main idle screw fully out so there is no chance of it touching. Now, look down the throat of the carb from the engine side. Adjust the vac screw so that the slide is fully bottomed out, flick the butterfly a few times so the slides lift and settle, just to make sure nothing is sticking. Now adjust the screw until the slide just starts to lift, use a torch on the air box side if it helps, do the same for each carb. Now wind in the main idle screw until it starts to lift the slides ever so slightly. Compare the gap, does it look the same? If so that’s close enough. I always vac gauge mine after anyway just to get that fine tuning. Never had a hanging throttle done this way.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline DomP

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Re: Doms CB550F1 project
« Reply #747 on: May 23, 2025, 09:08:41 PM »
Thanks Ken that's essentially how I did it previously but I've found it ends up with a lot of adjuster threads showing and the throttle stop cam cabpnt be adjusted to touch.  I'll have another look at it tomorrow and see where I'm going wrong.
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Oddjob

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Re: Doms CB550F1 project
« Reply #748 on: May 23, 2025, 09:33:31 PM »
I thought it was meant to have a gap Dom
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline DomP

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Re: Doms CB550F1 project
« Reply #749 on: May 23, 2025, 11:00:31 PM »
Maybe I'm talking about the wrong part, the off set bar with a hex section on the throttle bell crank.  I'll do a bench sync and take some photos tomorrow
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675