Author Topic: Doms CB550F1 project  (Read 209913 times)

Offline Laverdaroo

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Re: Doms CB550F1 project
« Reply #600 on: June 03, 2024, 10:12:19 AM »
Don’t forget,
Wheelie’s passed the ‘all girl school’ bus stop are compulsory


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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 #601 on: June 03, 2024, 10:58:25 AM »
Don’t forget,
Wheelie’s passed the ‘all girl school’ bus stop are compulsory

That's more likely than a stoppie!🤣

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1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Laverdaroo

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Re: Doms CB550F1 project
« Reply #602 on: June 03, 2024, 11:14:11 AM »
Don’t forget,
Wheelie’s passed the ‘all girl school’ bus stop are compulsory

That's more likely than a stoppie!

Sent from my iPhone using Tapatalk



Sent from my iPhone using Tapatalk
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 #603 on: June 03, 2024, 06:50:28 PM »
Did a sneaky first ride (proper countryside so no main roads)   

Some things no note and the reasons I ended it pretty quickly, I've got a hanging idle which revs up between gears, sometimes to high to be comfortable with.  Its definitely running rich which may be part of it?

Secondly when I got back and switched the key off it did a kind of intake of breath and popped a muted backfire, again this concerned me a bit so I'll wait some responses before I go out again.

Lastly, no speedo registering on my koso with daytona analogue to digital speed sensor as well as the well documented lack of rev counter
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Tony.B

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Re: Doms CB550F1 project
« Reply #604 on: June 04, 2024, 12:30:26 PM »
Did a sneaky first ride (proper countryside so no main roads)   

Some things no note and the reasons I ended it pretty quickly, I've got a hanging idle which revs up between gears, sometimes to high to be comfortable with.  Its definitely running rich which may be part of it?


Are you 100% sure carbs are balanced exactly? I remember back in my 400/4 days, that was always the giveaway that carbs needed balancing.

Offline DomP

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Re: Doms CB550F1 project
« Reply #605 on: June 04, 2024, 01:03:58 PM »
They're bench sync'd but not balanced as such, because it's a rebuilt engine I don't want to have it sat idling for long
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline McCabe-Thiele (Ted)

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Re: Doms CB550F1 project
« Reply #606 on: June 04, 2024, 01:25:06 PM »
We have an old floor standing fan that I use when tinkering to give an air flow over the front of the bike.
It used to be whiteish - with the ravages of time  its now beige/yellow.

I've brought it down from my garage loft ready for setting the dynamic timing and the carb sych.

Honda CB400NA Superdream (current money puddle)
Honda CB500 K1 (second money pit)
https://www.sohc.co.uk/index.php/topic,28541.0.html
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
This is a neat 500 restoration in the USA.
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

Offline DomP

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Re: Doms CB550F1 project
« Reply #607 on: June 04, 2024, 03:37:33 PM »
I have had this thought Ted, just I don't want the pistons and rings to suffer before they are bedded in
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline Laverdaroo

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Re: Doms CB550F1 project
« Reply #608 on: June 04, 2024, 07:28:40 PM »
Im with Ted on that, get some fans on it but keep yoiur time idling to a minimum to reduce the risk of glazing. I dont have fans so going to be carrying my guages with me on the test rides. Roadside fiddling always been a part of my motorcycling career but  that might be due to the amount of old and shagged out Ducati's I've had. ;D
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 #609 on: June 07, 2024, 07:51:14 PM »
The main problem I've caused myself is that I can't set the revs due to having no working rev counter.  I just can't get it to idle nice and even, when I blip the throttle the revs won't fall meaning I end up hitting the kill switch, it is pretty even across all four cylinders on my Morgan carb tuner though so that's a positive.

One other thing to note, sometimes when I turn the ignition on I get a pop/air type sound from around the battery or airbox.
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline davidcumbria

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Re: Doms CB550F1 project
« Reply #610 on: June 08, 2024, 08:36:10 AM »
I found the pilot airscrews have a much bigger effect than you’d think so try experimenting with them 1/2 turn further in or out and see what changes. Are all the cylinders running at similar temperatures - an infra red temp gun is cheap and useful.
500/4 in 79. No bikes for 30 years. 750/4 in 2013, 550/4 in 2023. Also own  R1100GS, RD350LC YPVS , Yamaha fazer 600, Yamaha XT250, BmwR80 , HondaVT1300, Royal Alloy GT125.

Offline McCabe-Thiele (Ted)

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Re: Doms CB550F1 project
« Reply #611 on: June 08, 2024, 10:53:29 AM »
What sort of gap did you have when you bench synchronised the carbs?
I went for zero on the 500 so even on 3 and a bit cylinders no issues with setting the idle.
On my 400 I used an odd sized drill shaft it was something like 3/32.
Reads as very difficult with no working rev counter.
Honda CB400NA Superdream (current money puddle)
Honda CB500 K1 (second money pit)
https://www.sohc.co.uk/index.php/topic,28541.0.html
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
This is a neat 500 restoration in the USA.
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

Offline DomP

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Re: Doms CB550F1 project
« Reply #612 on: June 09, 2024, 03:13:09 PM »
I missed these replies sorry folks.

An infrared temperature gun is something I keep meaning to get so I think I'll order one now David.  I've set my pilots to the standard 1 1/2 turns out but have not tried at 1 3/4.  As for gap Ted, I set it very much at the smaller end but forget what it was now, the rev counter issue is really not getting closer to solved, I need to email Koso to try and get to the bottom of it I think, I've made a rod for my own back by not using the same brand gauge as the speed sensor too.
1975 XS650B
1976 CB550F1 current project
2012 Triumph Daytona 675

Offline McCabe-Thiele (Ted)

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Re: Doms CB550F1 project
« Reply #613 on: June 09, 2024, 03:37:55 PM »
I missed these replies sorry folks.

An infrared temperature gun is something I keep meaning to get so I think I'll order one now David.  I've set my pilots to the standard 1 1/2 turns out but have not tried at 1 3/4.  As for gap Ted, I set it very much at the smaller end but forget what it was now, the rev counter issue is really not getting closer to solved, I need to email Koso to try and get to the bottom of it I think, I've made a rod for my own back by not using the same brand gauge as the speed sensor too.

Those tables show a wide range of 1-2 turns for the 550F,F1 & F2 069A type carbs Dom, are you definitely air leak free in all three areas between carbs and cylinder head?
 
I use a bit of alloy pipe as a listening tube to check for air leaks - it amplifies any sounds of air being sucked in - plastic pipe works but not as much amplification.
« Last Edit: June 09, 2024, 03:41:53 PM by McCabe-Thiele (Ted) »
Honda CB400NA Superdream (current money puddle)
Honda CB500 K1 (second money pit)
https://www.sohc.co.uk/index.php/topic,28541.0.html
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
This is a neat 500 restoration in the USA.
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

Offline Laverdaroo

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Re: Doms CB550F1 project
« Reply #614 on: June 09, 2024, 03:39:00 PM »
1 1/34 is base setting Dom, +/-  1/2 turn but it’ll be more I should think. Set em all at standard then work from there mate.


Sent from my iPhone using Tapatalk
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?))