Author Topic: The CB550 that came in from the cold  (Read 8531 times)

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Offline HondaMan

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Re: The CB550 that came in from the cold
« Reply #25 on: December 29, 2025, 12:03:06 PM »
Just a quick update: Found out why the clutch lifter wasn't working.


Fixed it  :P

What was "up" with the lifter?
See SOHC4shop.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book
Link to My CB500/CB550 Book: https://www.lulu.com/search?sortBy=RELEVANCE&page=1&q=my+cb550+book&pageSize=10&adult_audience_rating=00
Link to website: https://sohc4shop.com/  (Note: no longer at www.SOHC4shop.com, moved off WWW. in 2024).

Offline rb550four

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Re: The CB550 that came in from the cold
« Reply #26 on: December 29, 2025, 12:34:12 PM »
  Some guys use carb clean spray , I like to soak mine in carb cleaner ....it's getting hard to find here in NY  a bit toxic I guess  but that's what I use until I find a better way . Honda man is right , never do this stuff without eye protection !
And I have found if you can't get it clean with a spray can you may find it better with a cheap pancake compressor if you don't have a big one. One last thing , super glue for the corners of the float bowl washers.
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline newday777

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Re: The CB550 that came in from the cold
« Reply #27 on: December 29, 2025, 05:32:05 PM »
Just a quick update: Found out why the clutch lifter wasn't working.


Fixed it  :P

What was "up" with the lifter?
Check the spring in the pictures
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 1 K2, 4 K6, 1 K8, 1 F1, 1 F3
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #28 on: January 04, 2026, 10:32:25 AM »
  Some guys use carb clean spray , I like to soak mine in carb cleaner ....it's getting hard to find here in NY  a bit toxic I guess  but that's what I use until I find a better way . Honda man is right , never do this stuff without eye protection !
And I have found if you can't get it clean with a spray can you may find it better with a cheap pancake compressor if you don't have a big one. One last thing , super glue for the corners of the float bowl washers.
Thank you very much for reiterating these tips. I've had one close call with carb cleaner spraying back into my face, thankfully I do wear my glasses on shop days. And the thought has occurred to me several times that an air compressor would do a lot better than my soaking, picking, and scrubbing. Maybe if I time its usage while nobody is around to hear it. Say for instance, the EMT guy sleeping off the night shift whose space I'm borrowing.

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #29 on: January 04, 2026, 11:35:04 AM »
Just a quick update: Found out why the clutch lifter wasn't working.


Fixed it  :P

What was "up" with the lifter?
Check the spring in the pictures
Yeah, I should also elaborate that wasn't the only problem, just an oversight that was interfering with my adjustment of the lifter arm. HondaMan mentioned previously:

"First, I'll mention about the clutch plates you have: the 2.8mm thick plates are the ones Vesrah (i.e., generic imported plates) is lately selling in place of Honda's 2.71mm thick versions. In that regard, they should work OK."

The 2.8mm plates do result in a stack height that allows for adequate pressure plate separation while the clutch lifter arm is positioned correctly (horizontally aligned to arm and case markings). I had incorrectly assumed that I needed to increase the stack height from 31.6mm (with the 7 Vesrah plates), to something closer to 34.4mm (I assumed 7 factory plates would make this figure). I sought to accomplish this by swapping in three CB750 friction plates of 3.5mm thickness adding up to a stack height of 33.7mm (above wear spec as listed in my Clymer manual.

Now this is more or less the thought process I was approaching the problem with. Shifting problem=clutch problem, clutch problem: arbitrary stack value is lower than spec/ I think it's incorrect because it doesn't match what my books or the Internet says. Therefore the solution must be to come up with a new arbitrary stack height, replace parts until it's closer and then wonder why it still doesn't work..... I realize that I failed to consider the actual mechanics of this component and that's how something obvious like the lever spring having slipped behind the actuator went unnoticed while I was fixated on the friction plates.

The only parts I ended up replacing were the springs (swapped them out for weaker ones) and one friction plate. The clutch seems fine now, when I ride again I'll see how the bike shifts.

It's awesome to have access to the knowledge, knowing how to apply it is what takes real skill.
« Last Edit: January 04, 2026, 11:37:29 AM by ThelassianLupus »

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #30 on: January 05, 2026, 03:22:01 AM »
Anyway, on to my next question.

I found these jet replacement kits that I had purchased when I first got the bike. I'm pretty sure I got them from Common Motor Collective. I don't believe they are genuine Keihin parts, so the only pieces I'm considering to use are the o-rings.

I've replaced the drain plug rings, and I'm looking at other o-rings to swap. The replacement main jet from the kit seems to have a ring that's both too small and too wide. The dry fit was too tight when I tried seating the new main jet, it wouldn't go in completely. Yet it seems to not fill the groove on the main jet entirely either. I suppose this is why I've heard that the factory main jet has a "custom" o-ring.

My questions are, how would I know if I needed to replace this ring? And if I need to replace one, should I replace them all across the three other carburetors?

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #31 on: April 06, 2026, 05:13:51 AM »
Long overdue update, not much has changed but I still want to keep the thread.

I've moved on from the carbs, they're rebuilt and waiting for me to finish checks to the wiring harness before going back on the bike. Despite a long winter, riding season has already begun here in Maine and I'm itching to get on the road. The biggest hurdle to that right now is repainting the gas tank and body panels. I have my Eastwood order set out on the bench, so that this Friday when it gets to be over 50° outside I can get started.

I recently had an awesome opportunity to travel to New Hampshire with my dad and visit Steve from hondarestoration.com. Got to look through his collection, buy some parts, and met two forum alumni AlanF and Newday777! Super great to chat with you both. Look forward to running into you again.

Offline denward17

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Re: The CB550 that came in from the cold
« Reply #32 on: April 06, 2026, 06:12:35 AM »
Good Luck on the paint, I'm sure it will turn out great.
Yes, Alan and Stu are good people....

Offline newday777

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Re: The CB550 that came in from the cold
« Reply #33 on: April 06, 2026, 07:09:52 AM »
It was great meeting you and your dad too! Hope to catch up with you again.
Paint likes 70° and above....though we could be seeing that here on Friday.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 1 K2, 4 K6, 1 K8, 1 F1, 1 F3
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline HondaMan

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Re: The CB550 that came in from the cold
« Reply #34 on: April 06, 2026, 09:28:56 AM »
Sorry to "drop out" of the thread: my wife got real sick and was undergoing many (MANY) tests and [bad] doctor visits, trying to pinpoint the cause. I was a little too occupied with that stuff. :(
See SOHC4shop.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book
Link to My CB500/CB550 Book: https://www.lulu.com/search?sortBy=RELEVANCE&page=1&q=my+cb550+book&pageSize=10&adult_audience_rating=00
Link to website: https://sohc4shop.com/  (Note: no longer at www.SOHC4shop.com, moved off WWW. in 2024).

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #35 on: April 06, 2026, 12:24:25 PM »
Mark, I'm really sorry to hear that. Always glad for your input, no apologies needed.

How is she now?

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #36 on: April 12, 2026, 07:24:20 AM »
Thanks for the clarifying info Stu. I was planning to try spray painting 2k epoxy primer in 49 degree weather. From further internet research, it seems I wouldn't have gotten away with it. I have a different approach in mind, I think my buddy will lend me a space I can get above 65 to work in.

Instead of painting I used the nice weather to do more sanding and stripping.

Offline denward17

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Re: The CB550 that came in from the cold
« Reply #37 on: April 12, 2026, 07:28:26 AM »
Thanks for the clarifying info Stu. I was planning to try spray painting 2k epoxy primer in 49 degree weather. From further internet research, it seems I wouldn't have gotten away with it. I have a different approach in mind, I think my buddy will lend me a space I can get above 65 to work in.

Instead of painting I used the nice weather to do more sanding and stripping.


You can never do enough prep work prior to painting....

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #38 on: April 12, 2026, 07:36:15 AM »
These actually are not the final pictures of how much of the surface I could get down to bare metal.

I used multiple techniques,
drill with stripping pad to cover the most area,
sanding with 80 grit by hand,
coating with JASCO paint & epoxy remover and leaving overnight, coming back the next day to scrub and sand more by hand, finally with some brush and abrasive attachments on a Dremel getting into the hard-to-reach spots.

Some discolored spots and drip marks are from phosphoric acid etch I applied when experimenting with what removed paint and rust.




Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #39 on: April 12, 2026, 07:53:24 AM »
By far the most difficult spots to reach into were around the mounting points at the seat tab,



 and where those frame bushings are supposed to catch in this "shoulder" area.



And there was the gas cap's bracket that was hard to get under. Again I did ultimately manage to take more old paint off, and I cleaned up all the rust seen in these pictures. I found the Dremel flap wheel attachment to be super helpful with this.

I'm hoping that using an epoxy primer now will, a) still form a strong bond even over areas that still have a little paint left and,
b) form a resilient layer that could withstand corrosive fuel in the case that pinholes have formed in those rust spots previously mentioned. Maybe this is too much to hope for, I could(should) do more research into this but if anyone seriously objects to my plan I'd welcome the advice.

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #40 on: April 12, 2026, 07:57:43 AM »
Bonus!
A new dilemma that will further delay my first-ride-of-the-season.
I opened the alternator cover while checking electrical connections. Tried to be super careful with the gasket, but ended up tearing it  ::). But while I'm waiting for 4into1 to send a new one, how should I deal with this gritty stuff I found back there? I'm guessing the rotor shouldn't look like that.




Offline MauiK3

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Re: The CB550 that came in from the cold
« Reply #41 on: April 12, 2026, 08:53:57 AM »
I would think brake cleaner would flush out any loose stuff. If you have a way to dry things out you can clean windings with a water based cleaner, as long as a good dry out is possible. I wouldn't use anything that may affect the coatings on the wires. If you use brake cleaner try it on an area and be sure whatever you are using doesn't soften anything.
Many years ago I worked on submarines. When we would overhaul the big motor/generators the stators and rotors would be put into what amounted to a dishwasher (very large one) and washed, then they were baked dry. Got all the stuff out of the windings.
1973 CB 750 K3
10/72 build Z1 Kawasaki

Offline ThelassianLupus

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Re: The CB550 that came in from the cold
« Reply #42 on: April 12, 2026, 10:11:40 AM »
Many years ago I worked on submarines. When we would overhaul the big motor/generators the stators and rotors would be put into what amounted to a dishwasher (very large one) and washed, then they were baked dry. Got all the stuff out of the windings.

Very cool! That must have been some operation. Did they have the same sort of laquer coating as on our Hondas? I've seen it shown elsewhere that some Auto parts are "dishwasher safe". It got me wondering if any home mechanics have set up dedicated parts washing dishwashers in their garage.