Topic: Dad's 1978 Honda CB550k

[newday777]

Here's an air box

http://forums.sohc4.net/index.php/topic,192816.msg2202792/topicseen.html#new

[joegeis]

Here's an air box

http://forums.sohc4.net/index.php/topic,192816.msg2202792/topicseen.html#new

looks like the spring is the only piece this contains that I am missing. Did the '75 CB550F not use a "lid" as my K model did?

[newday777]

Here's an air box

http://forums.sohc4.net/index.php/topic,192816.msg2202792/topicseen.html#new

looks like the spring is the only piece this contains that I am missing. Did the '75 CB550F not use a "lid" as my K model did?

I have no idea

[BenelliSEI]

I think I made one of those springs with a long, stainless hose clamp, squashed to size. All it does is keep the air filter up against the inlet opening…..

[grcamna2]

You need the cover for a sealed airbox.

[joegeis]

I think I made one of those springs with a long, stainless hose clamp, squashed to size. All it does is keep the air filter up against the inlet opening…..

Bad news - I can't find the pieces that go in the bottom of the airbox, for the exhaust recovery. I must have scrapped them before the last garbage day

Good news - I installed the Uni foam filter I had on hand. It has a good tight fit. I wedged a bit of folder cardboard where the spring goes and it is pressed firmly against the opening. I think it's creating a good seal. Everything feels well seated and firm.

I confused myself looking at the vent and fuel nipples, but I worked it that the "higher" of the two (with a bit of a bulbed end) is for fuel and the other is for venting. I just don't remember if a hose is supposed to connect to the vent or if it just stays as is.

[joegeis]

IT'S ALIVE! Fired on the first crank Choke all the way out brought it very quickly up to 4,000 RPMs, so I just feathered the throttle to keep it between 1k-2k until the engine was warm. It was able to hold a steady idle at 1,050 RPMs once warm. There is a clear and obvious clanking while the RPMS are coming down. I have no experience diagnosing by sound, but could it be the cam chain? I have not set the tension yet (about to go do that after posting this!). Next I'll check the points and adjust the timing and see how she does. If all is good I might throw the tank on and take a very cautious lap around the block (40 year old wheels, bearings and suspension still!).

Oh, this was with the old spark plugs still. I wasn't when I should throw the new ones in.  I'll put new ones in when I start it next.

Anything else you guys can hear in the video? I'll take another one with the camera close to the bike for better audio.

VIDEO

[newday777]

Well done. Sounds good for a first start up.
The clanking is the primary chain slapping the cases from the carbs out of synchronization. That puts uneven pressure on the crank as it's idling and thus the primary chain bouncing to the tune of the uneven fueling of each cylinder.
Once you do the cam chain adjustment, adjust the valves, the points and timing then do the carb sync, and the primary chain should quite down so a smooth purring motor.

[newday777]

And you can back off the choke idle speed adjuster to get the choke idle down to around 1500-1800(or what ever the manual says)

[joegeis]

Thanks Stu! I had no idea out of sync carbs could cause such a racket! I did the points, timing, cam chain tension and valve clearances tonight as well. Honestly everything was pretty much already dead on, but I went through it all anyways. I have a carb sync tool coming this week, so I'll get the carbs done soon.

Tomorrow I'm going to try and get both wheels off and torn down so I can take the rims into the powdercoating shop on Monday. My swingarm bushings just arrived today, so I'll maybe get to those while the rear wheel is off too. I imagine I'll be busy with other chores around the house most of the day tomorrow, but we'll see. Hearing that thing run has REALLY got me excited now! I was also happy to hear how good the pipes sounded. No rattling at all.

[newday777]

No doubt, I bet you were stoked.

If you are getting new spokes, just cut off the old spokes with a 4" grinder. Much faster than trying to loosen the nipples from each spoke.

[joegeis]

that is a great idea, thanks!

[flatlander]

indeed, sounds good. as stu says, a proper carb sync and all the other routine adjustments should make it smoother.
do you have the original honda workshop manual? if you do the 3k mile maintenance schedule, it will take care of all the basic things.

you can set the idle to 1100-1200rpm. that's a bit higher than the manual states but works out better.

[joegeis]

Got the wheels off the bike and been cleaning parts like crazy! I need to get the tires off the wheels and then cut the spokes so I can bring in empty rims to the shop for sandblasting and powder coating. I thought I could muscle off the tires, but they are hard as rocks! I've got some tire spoons coming in the mail, so in the meantime, I've taken apart and cleaning the front and rear brake systems. I will replace the wheel bearings once the wheels are rebuilt and I have them back from the shop. The front was completely seized up. I've got the master cylinder marinating in the ultrasonic to see if I can get it to free up. If not, I'm going to have to replace it, which I would prefer not to do. The pad is also stuck in the caliper. I'm hoping that once I free up the MC, I can use it and the new brake lines to push the pad and piston out. I've got so much taken apart at the moment, that I've been putting pieces in bags to try and keep everything straight, but I have a really bad memory, and I already know its going to be a struggle to get everything back in its proper place! I still have the swing arm bushings to replace, which I might tackle this weekend.

Also, how does this rear sprocket look? Time for a replacement? It has about 23k miles on it.


I noticed a few drops of oil below the engine on the floor. Making a mental note, but thats probably a problem for future me.

[CycleRanger]

Don't forget that you still need to determine the source of that piece of steel you found in the oil pan.

[grcamna2]

The rear sprocket still looks good,imo.

[joegeis]

Don't forget that you still need to determine the source of that piece of steel you found in the oil pan.

I HAVEN'T FORGOTTEN!! I'll add it to the "to-do list" on the top post just in case

I'll get into the transmission once the bike has wheels and brakes again!

[joegeis]

The rear sprocket still looks good,imo.

Thanks!

[Stev-o]

I've got so much taken apart at the moment, that I've been putting pieces in bags to try and keep everything straight, but I have a really bad memory, and I already know its going to be a struggle to get everything back in its proper place!

A lot of us take a lot of pics upon disassembly to refer to when putting back together. Also, the fiche is a big help showing placement as well as part numbers you can use when ordering.
Suggest you bookmark it...

https://www.partzilla.com/catalog/honda/motorcycle/1978/cb550k-a-550-four-k

[RAFster122s]

SohRon's cb550 restoration & reassembly guide is priceless

[CycleRanger]

SohRon's cb550 restoration & reassembly guide is priceless

http://forums.sohc4.net/index.php/topic,151576.0.html

It really is one of the finer things on the internet. Should be a book.

[joegeis]

Had to take the tires into a shop to get them off! They were hard as rocks. But its done. I cut off the spokes (thanks for the tip - it was very fast and easy!) and stripped everything down to be ready to get powder coated! This weekend I'm going to tackle the fork rebuild and steering column bearing upgrade. I don't have my new springs from Ikon yet, but I figured I should be able to fish the old ones out and replace while the forks are still on the bike when they arrive. I'll go ahead and polish, replace the seals and boots and refill with 10wt fork oil while its all apart anyways.

I ended up ordering a new master cylinder. I could not get the old one unseized. Once that arrives, I'll use it to pop out the old pad and piston, which are still lodged in the caliper! Once the I have the wheels back, I'll work on replacing those bearings. I almost forgot I still need to do the swing arm bushings before the wheels go back on too!

[joegeis]

Fork rebuild is complete. The oil in there was black with a bit of a green hue, and smelled like something rotten. It was the worst smell I've experienced in a garage... Otherwise, the forks and internals were in good shape. Someone had definitely done the forks before, because there was already some marring on them from prying out old fork seals at some point. 160mLs of clean and fresh 10wt fork oil went back in. Also have those Ikon progressive springs coming next month, which I'm hoping I can easily pop in with the forks still on the bike!

I will take a picture tomorrow, but I have one hell of a "class 2" (for my Army buddies) oil leak. It appears to be coming from the oil pan seal. I must not have gotten it seated right when I put everything back together. I remember it feeling like it just didn't want to sit in the groove nicely  Once again, I'll deal with that when the bike is on wheels again.

Powder coating shop is closed Saturday and Sunday. I'll hope they are open Monday (I'm off work), so I can get the wheels over there ASAP.

Tomorrow:
Steering bearing
Swingarm bushings

Thanks for the link to the guide, I'm sure it will come in handy when I start reassembling!

[RAFster122s]

You are initiated into the fish oil fork oil club. Hopefully the fluid had been changed at some point, but doesn’t sound like it. The fish oil that Honda first used reeks to high heavens…as you found.
 Congrats on the fork seal replacement…

[joegeis]

You are initiated into the fish oil fork oil club. Hopefully the fluid had been changed at some point, but doesn’t sound like it. The fish oil that Honda first used reeks to high heavens…as you found.
 Congrats on the fork seal replacement…

Thanks, I hate it.

Also, thought it was interesting that my fork internals were different than what was in the manual, and what I have seen others have in Youtube videos. It was still clear and obvious how it worked, but it was different. The seals and boots still worked fine.


I completed the steering bearing job this weekend as well, which went pretty smoothly. I needed to buy a 23mm and 30mm socket (my adjustable wrench wasn't doing the job), and make a bearing driver out of 1.25" steel pipe, but it was no big deal. It was very crusty and I'm glad I decided to take on this step!


I also dropped the wheels off at the powder coating shop, although I was floored they said their backlog was 2-3 weeks right now! I might have time to dig into the transmission and find where that missing tooth came from while I wait. I might try to do the wheel bearing replacements on the hubs in the meantime too. (Not sure if I need the weight/leverage of the whole wheel in order to get the old ones out).