Author Topic: Dad's 1978 Honda CB550k  (Read 40527 times)

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Offline Jan187

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Re: Dad's 1978 Honda CB550k
« Reply #425 on: September 22, 2025, 12:00:38 AM »
The shock bottom clevis itself is asymmetric and looks to be in the wrong direction (the koni logo is now on the inside and shock looks like touching the chain guard)
I guess the bolts are not the original ones, they look rather new and nice, are they the same length?

Offline newday777

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Re: Dad's 1978 Honda CB550k
« Reply #426 on: September 22, 2025, 01:59:05 AM »
You have the wrong bolt in that shock. It isn't supposed to be that long or have a nut on the end and is too small diameter. That is your problem.
The shocks are designed to have threads in the bottom to screw the proper bolt length and size into.
« Last Edit: September 22, 2025, 02:01:03 AM by newday777 »
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, 2 K4, 2 K6, 1 K8
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 joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #427 on: September 22, 2025, 06:34:15 PM »
Oh man, thank you guys! It was staring me right in the face and I couldn't see it. Yes, those are the wrong bolts. I believe they came with the Ikon shocks. The originals would not work, but I don't remember why. I'm sure I still have them, so I'll investigate further!

I was really scratching my head on this one!

Offline newday777

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Re: Dad's 1978 Honda CB550k
« Reply #428 on: September 22, 2025, 07:14:18 PM »
Oh man, thank you guys! It was staring me right in the face and I couldn't see it. Yes, those are the wrong bolts. I believe they came with the Ikon shocks. The originals would not work, but I don't remember why. I'm sure I still have them, so I'll investigate further!

I was really scratching my head on this one!

Did you buy them new from Ikon that way?
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, 2 K4, 2 K6, 1 K8
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 joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #429 on: September 24, 2025, 09:24:56 AM »
Yes. They had a pre-installed bushing, so could not use the oem bushing or bolt. Im traveling for work right now, but will investigate this weekend. It was installed two years ago and I dont exactly remember the details.

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #430 on: October 01, 2025, 07:34:04 PM »
So I think I've found my smoking gun for the fast idle and touchy advance. I actually replaced the whole advance mechanism with an aftermarket one from DSS in 2023 (a few pages back in this thread). I pulled it off, and pulled the original one out of the box (thankfully I kept it!) to compare. It looks like I probably did snip a ring off the old springs from the way they look, but did not clean it up. It was really varnished and sticky with baked on grease. The springs have good tension and feel strong. My new one is clean and well greased, but the springs are much weaker. It takes almost no effort to pull them out. I imagine this is likely what is causing the bike to want to stay at full advance constantly.

I'm cleaning up the old one. I've degreased it and have it sitting in some vinegar (I'm fresh out of Evaporust!) overnight. Tomorrow I'll lube up the old one and clean up the shaft and reinstall. I strongly suspect my idle will return with much more snap!

I kind of forgot about the shock issue... I'll have to come back to that this weekend!.

Also... because I didn't notice before I took them apart, does the "lobe" on the cylinder go towards the 1-4 or the 2-3 when reassembled?

« Last Edit: October 01, 2025, 07:48:14 PM by joegeis »

Offline denward17

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Re: Dad's 1978 Honda CB550k
« Reply #431 on: October 02, 2025, 02:39:03 AM »

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #432 on: October 02, 2025, 07:13:36 PM »
So, I reinstalled my cleaned up original advancer, and the old problems returned. The bike struggled below 2,500 rpm and then would slingshot up from 2,500 rpm as the advance finally opened up. The springs were too tight. So what is Goldilocks to do? I ended up taking one of the softer aftermarket springs and one of my shortened OEM springs on the OEM advancer - and it worked like a charm! Was much easier to set timing, bike idles at 1,000-1,200 rpm nicely, revs up smoothly with no "slingshot" effect, and comes back down to a consistent 1,200 rpm idle. I took it for a test ride, since the issues would get worse when the bike was good and hot, and the bike came back to 1,200 at every stop sign. A bit unconventional, but I think I've got my solve!

I also flipped that shock around so it was seated correctly and is no longer rubbing. I was mistaken about the bushings. My originals are still in place. I remember thinking they looked fine, and like a hell of a pain to remove at the time, so I left them alone. I do have Honda replacements that I never used on hand, just in case.

Next up on the to-do list is to replace my front brake line. I have a custom length HEL steel line that I'll run down to the caliper pipe. I'm deleting the pressure switch behind the headlight and wiring up to the master cylinder switch. I also need to take my tach apart and rebuild it. It likes to stop working sometimes and needs a good whack ;) Oh, I also have noticed my instruments have no glow anymore. I can't read them at all in the dark. Is there a fix for this? Or do I need to replace the faces?

David Silver Aftermarket spring on the left, OE spring on the right:
« Last Edit: October 02, 2025, 07:17:22 PM by joegeis »

Offline grcamna2

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Re: Dad's 1978 Honda CB550k
« Reply #433 on: October 02, 2025, 08:48:49 PM »
Good fix on the advancer Joe.
75' CB400F/'bunch o' parts'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #434 on: October 03, 2025, 10:44:15 AM »
Back to an old topic. If you remember, when I first dropped the oil pan two years ago, I found a transmission "dog ear" in the pan. I cautiously ignored it and carried on with the rebuild. Well, when I dropped the oil pan this summer, I found another one. I've also noticed a little bit of clunk when shifting from 1st to 2nd gear. I anticipate needing to complete a bottom end rebuild at some point in the future, but I assumed it would be really hard to find the damaged parts available for replacement without having to buy an entire parts bike or engine at least.

Well I found this on ebay yesterday, and was able to scoop it up for $40! It's just going on the shelf for now, but I'm happy I've at least got a backup on hand when the time finally comes!

I circled what I think are the pieces that broke off and I found in the oil pan.

I've also got an ebay alert setup for a CB650 cam. If I can get one for a good price, I would like to experiment with that upgrade in the future.
« Last Edit: October 03, 2025, 10:47:01 AM by joegeis »

Offline grcamna2

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Re: Dad's 1978 Honda CB550k
« Reply #435 on: October 03, 2025, 11:23:37 AM »
Back to an old topic. If you remember, when I first dropped the oil pan two years ago, I found a transmission "dog ear" in the pan. I cautiously ignored it and carried on with the rebuild. Well, when I dropped the oil pan this summer, I found another one. I've also noticed a little bit of clunk when shifting from 1st to 2nd gear. I anticipate needing to complete a bottom end rebuild at some point in the future, but I assumed it would be really hard to find the damaged parts available for replacement without having to buy an entire parts bike or engine at least.

Well I found this on ebay yesterday, and was able to scoop it up for $40! It's just going on the shelf for now, but I'm happy I've at least got a backup on hand when the time finally comes!

I circled what I think are the pieces that broke off and I found in the oil pan.

I've also got an ebay alert setup for a CB650 cam. If I can get one for a good price, I would like to experiment with that upgrade in the future.

Good 'find', does the same seller have the shift forks,just in case?
75' CB400F/'bunch o' parts'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #436 on: October 03, 2025, 05:31:57 PM »
Looks like it I think? https://ebay.us/m/qxlTEl This seller has a TON of Honda SOHC parts available.

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #437 on: October 05, 2025, 06:11:01 PM »
Took my daughter on the bike to go get ice cream yesterday. It was a really nice time! She is 12 years old and loves the bike. Maybe someday I'll pass it down to her :)

Anyways, I did notice on a longer ride a bit of idle hang again. It seems like its back to a lesser degree when the engine is good and hot. Maybe I'll try snipping half a link off that weaker aftermarket spring. I want to be cautious of making that one too tight as well.

I know I said I was planning to leave "much of the patina" when I started this project, but I think my tastes are changing. While I'm by no means going for show quality, buffed and polished, I did want to clean up some of the heavily corroded aluminum. I took the stator cover and the plate behind the shift lever off to give them a clean. My intent is to give the aluminum a brushed appearance. I also wanted to restore the black lettering on the stator cover. I thoroughly cleaned and degreased everything then hit the stator cover with 220 grit dry to smooth out the scratches and chips a little bit. I didn't try to get them all out. Then I went 400 wet and then green scotchbrite. After that I masked off the letters and applied black VHT paint. Tomorrow I'll come back with 400 grit and carefully sand down the raised letters to remove the paint. I hope it works! I have some Boeshield T-9 to protect the raw aluminum after I'm done painting and sanding.

Also, I noticed a good amount of oil coming from the shift mechanism. I'm sure the seal in there is shot. I'm wondering if this is where my "oil pan leak" was actually coming from all along! I assume there is no way to replace that seal without opening up the bottom end? I'm sure I'll be doing the bottom end rebuild at some point in the future, so maybe I'll save it for then, but if its not too painful, I would be willing to fix it now to keep the oil from leaking.

Let me know if anything else behind here looks like it needs attention!

Before


During


After


My fancy paint booth:
« Last Edit: October 06, 2025, 07:01:29 PM by joegeis »

Offline grcamna2

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Re: Dad's 1978 Honda CB550k
« Reply #438 on: October 06, 2025, 11:34:59 PM »
The covers look good.
75' CB400F/'bunch o' parts'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline BenelliSEI

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Re: Dad's 1978 Honda CB550k
« Reply #439 on: October 07, 2025, 09:49:05 AM »
The covers look good.

+1 nice looking.

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #440 on: October 07, 2025, 08:13:18 PM »
Tonight I replaced the shift shaft seal (so much easier than I expected!) which should help make this even just a bit less leaky. Everything else looked good, so I reinstalled my covers. They look so good, it makes me want to clean up more of the bike, lol.

I've also decided I'm going to eventually bob the fenders and have the chrome removed. I'll brush the steel like I did the aluminum covers and keep them coated in T-9 also. If they start to rust, I'll clear coat them instead.


Offline denward17

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Re: Dad's 1978 Honda CB550k
« Reply #441 on: October 08, 2025, 02:06:07 AM »
Nice looking bike Joe.....which handle bars are on it?

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #442 on: October 08, 2025, 12:46:14 PM »
Nice looking bike Joe.....which handle bars are on it?

Those are the cheap superbike bars from Common Motor Collective. They are nearly identical to the bars on my street triple, and they are just perfect for me. I love them!

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #443 on: October 08, 2025, 12:47:55 PM »
So I left the house on the bike this morning and a few blocks from home I lost power! I must have broken something or hooked something up wrong when reinstalling the alternator! I pushed the bike home and put it on the charger. I'll take it apart again and see what I could have messed up. It seemed pretty simple, so not sure what could have been done wrong!

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #444 on: October 10, 2025, 03:18:26 PM »
Power issue resolved (I think)! I replaced the ground wire bullet connector coming from the alternator. It was pulled a little loose when disconnecting it the first time.

I am starting to notice some of that advance timing hang. I think my clever trick of using one tight and one loose spring didn't quite work as well as I had hoped. I'm considering purchasing a NOS advance mechanism, but they are pricey! I've also found posts talking about these Yamiya springs from Japan for the CB750. Will they work on the CB550? I can't find anything that says if the springs are the same or not. It would cost me $80 for those two little springs, so would much rather be sure that wing it!

Offline newday777

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Re: Dad's 1978 Honda CB550k
« Reply #445 on: October 10, 2025, 03:54:07 PM »
Yes the springs are the same.
The whole points plate assembly is the same for the 500/550 and the 750. Always have been since the 70s.
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, 2 K4, 2 K6, 1 K8
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 scottly

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Re: Dad's 1978 Honda CB550k
« Reply #446 on: October 10, 2025, 04:17:09 PM »

The whole points plate assembly is the same for the 500/550 and the 750.
The advance mechanisms are different between the 500/550 and the 750.
Don't fix it if it ain't broke!
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Offline scottly

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Re: Dad's 1978 Honda CB550k
« Reply #447 on: October 10, 2025, 06:30:02 PM »

I am starting to notice some of that advance timing hang. I think my clever trick of using one tight and one loose spring didn't quite work as well as I had hoped.
Try cutting a coil off of the new loose spring, or at least squeeze the end loops closed some. It looks like it isn't stretched or preloaded at all.
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline joegeis

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Re: Dad's 1978 Honda CB550k
« Reply #448 on: October 10, 2025, 08:46:25 PM »
I suppose its worth tweaking one of those new springs before dropping $80 on a NOS advance mechanism or those new Yamiya springs! I'll try squeezing the loops closed a bit more.