Author Topic: '77 CB550F - budget project  (Read 2533 times)

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Offline jabar

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'77 CB550F - budget project
« on: June 14, 2011, 09:19:08 pm »
Howdy folks,

New to the forums, generally new to all things motorcycling. I really didn't want to write-up a project thread because it would be a letdown if I failed to complete it, but I believe it will help facilitate my learning of All Things SOHC/4.

Somehow, a few months ago, I got motorcycles in my blood. As I continued researching my desire festered but I found myself rather broke. After weeks of CL trekking I settled on a '77 CB550F. Tonight is her fourth night in my possession.

A little background on the bike. She was last running somewhere around 6 months to a year ago, but was (presumably) last ridden often back in '05 when the PPO (or PPPO) wrecked her. The PO purchased her when his friend, the PPO, left the state, but the PO had other projects to tend to, which is why I came into the picture. When last running the PO cited that the bike would die after running 5 minutes or so, which he believes could be the electrical system.

I decided to take up the challenge to restore the CB550F to her former glory. Note that my mechanics' experience previously consisted of inflating tires, changing oil and installing a hitch. I didn't know all the parts to a motor vehicle until very recently. Despite this, I am still confident I can figure this out (with some help). For now, getting her running (well) is priority, with replacing broken parts to OEM or equivalent along the way. My budget is tight: I can afford supplies and small expenses, but the goal here is to get her on the road, not to customize her (just yet).

The Good:
  • Engine turns over (confirmed)
  • Transmission reportedly good
  • Frame OK
  • Bike metal in good cosmetic shape, very little extraneous rust.

The Bad:
  • Rear wheel askew (replacement)
  • New chain and perhaps sprockets required
  • Tank severely dented (replacement probably required)
  • Seat damaged (reupholstering or replacement)
  • Electrical system suspect
  • Needs front fender, side fairings, replacement Rear Fender B (plastic)
  • Needs replacement airbox rubbers

The Ugly:
  • Has upside down dirt bike handlebars installed (ha ha)

What I've Done So Far:
I've been working on her each day so far and have accomplished:

Tank/Seat removal
Airfilter/Airbox/Rear Fender removal
Carburetor removal

The Plan So Far:
This is my current plan, but as I discover more issues it will obviously get adjusted accordingly. Tomorrow I will start on the carburetor (using Simple Green, still need to work out the procedure). At the same time, I will begin researching the electrical system and test connections with my multimeter.

At the moment I have no desire or capability to remove the engine from the frame. It turns over fine with the kickstart, but I haven't measured the exact compression (don't have a vacuum gauge). I do want to clean the exterior: almost every component on the bike is covered in dust/dirt. I guess elbow grease is the way to go (with some Simple Green perhaps)? Any suggestions to make it look less dull? (yes I will probably do a search on this site when the time comes)

Another problem I ran into is the discovery that the airbox -> carb rubbers are disintegrating, and they seem very hard to come by. edit: looks like ClassicMotorcycleSolution has them, will need to order.

I'll have updates with the progress of the carbs and more photos!
« Last Edit: June 14, 2011, 09:20:53 pm by jabar »

pat english

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Re: '77 CB550F - budget project
« Reply #1 on: June 15, 2011, 01:02:03 am »
sweet.nice start.

Offline sopo400f

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Re: '77 CB550F - budget project
« Reply #2 on: June 15, 2011, 03:33:43 am »
Maybe you should try to find a cheap donor bike with a stuck motor. Snag all the parts you need in one shot.......?
1975 cb400f blue

Offline 70CB750

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Re: '77 CB550F - budget project
« Reply #3 on: June 15, 2011, 05:00:54 am »
Get carburetor cleaner, it works miracles, but gotta watch for gaskets and things not metal.  Quick spray will not hurt it, soaking eventually will - don't ask how I know  ;D

And good luck with the project, bit every day is my approach too.

I actually found a book in local library on restoring vintage motorcycles.  I am an old(er) gearhead, but it was still very interesting reading since my experience is mainly with Jeeps and cars (plus Russian tanks LOL)  - I would suggest to check on those books for tips and tricks and general info.

Offline jabar

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Re: '77 CB550F - budget project
« Reply #4 on: June 15, 2011, 06:14:59 am »
Maybe you should try to find a cheap donor bike with a stuck motor. Snag all the parts you need in one shot.......?
Thanks for the tip. I'll keep an eye out on CL, but the central Texas area has quite inflated prices on bikes (being summer I guess). The donor bike would need to be very cheap for me to consider.

Get carburetor cleaner, it works miracles, but gotta watch for gaskets and things not metal.  Quick spray will not hurt it, soaking eventually will - don't ask how I know  ;D

And good luck with the project, bit every day is my approach too.

I actually found a book in local library on restoring vintage motorcycles.  I am an old(er) gearhead, but it was still very interesting reading since my experience is mainly with Jeeps and cars (plus Russian tanks LOL)  - I would suggest to check on those books for tips and tricks and general info.
I've been reading a lot about Simple Green here. I don't have a problem working with standard carb cleaner if that's a better way to go. This site has an absolute ton of info; I have the OEM service manual downloaded and might get a Clymer manual copy for noob support. Also I love coming home from work and working on the bike.

Offline jabar

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Re: '77 CB550F - budget project
« Reply #5 on: June 15, 2011, 07:31:18 pm »
Today I cracked apart the carbs and began cleaning. I took my time learning their configuration so I only finished soaking one of them. The bowls weren't that bad, and after about 1.5 hours in Simple Green and a little scrubbing they cleaned up just fine. Right now they're sitting til tomorrow. The only concern I have is that the bowl O-ring is quite flat, and there was some evidence on other bowl lips of leaking. Might need to look into a gasket kit in the future.

I managed to break a screw which holds the throttle axle bar above the carb rack... hopefully I can find a replacement for it. I'll need to drill out the rest of the screw.

Pictures will follow tomorrow. I'm exhausted from work and I have an early morning/long day tomorrow. Otherwise I have a

Offline Bankerdanny

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Re: '77 CB550F - budget project
« Reply #6 on: June 16, 2011, 08:10:55 am »
be very thorough, pull and separate all the jets, spray carb cleaner through the misc orifices. Some of the fuel metering holes are every small and it doesn't take much gunk to clog them.
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Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200

Offline hyde7278

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Re: '77 CB550F - budget project
« Reply #7 on: June 16, 2011, 09:07:32 am »
get a peice of metal guitar string to use to clean the passages
78 CB550 (FOR PARTS)
76 CB550F

Offline immortal

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Re: '77 CB550F - budget project
« Reply #8 on: June 16, 2011, 09:48:06 am »
You got yourself a really nice little project and a nice start. Good luck with it!
Sometimes...the hard thing and the right thing are the same thing!

1976 CB750F "Pegasus Bike"

http://forums.sohc4.net/index.php?topic=80492.0

Offline jabar

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Re: '77 CB550F - budget project
« Reply #9 on: June 19, 2011, 07:22:20 am »
I ended up taking Friday off, then Saturday got back to the carb work. Two complete units are now thoroughly cleaned. The jets were in good condition anyway, only the bowls were a bit grimy but Simple Green cleaned it all up. I ended up losing the 7mm head hex bolt used in the attachment of the needle jet 'piston'... absolutely no clue how it went missing. Fortunately I found a metric supply company nearby which can fix this issue (and the issue of the broken throttle axle screw) during the weekdays.

I need to put the carbs on hold for now as I need to replace the fuel lines from the T to the petcock and the two aforementioned screws. One of the POs installed cone fuel filters which I guess I will replace... they sure kept the carbs real clean.

I also need to purchase those replacement airbox rubbers. Once the carbs are assembled and the airbox assembly cleaned, the electrical will be next. Although the PO suspected electrical problems I'm not sure if that's the case (which means less work for me). If the electrical is OK, then I only need a battery and figure out the fuel tank situation and the bike should fire up!


Two down, two more to go. I will reassemble the pair before embarking on the other two. Will be getting a 1/4" fuel line and possibly a replacement fuel filter (what do you think?).


The second carb unit. Note that the top is off, as I am missing that dratted screw. Column all lubed up and ready to go.

Offline jabar

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Re: '77 CB550F - budget project
« Reply #10 on: June 25, 2011, 01:27:02 pm »
A quick update. Replacement metric hex bolts were found at a pretty awesome specialty bolt shop in town which set me back $0.50. Now I have the two complete carb units assembled. I'll need to procure a replacement 5.5mm ID fuel line for both halves, so that is the current holdup.

The floats on my carbs had identical measurements, somewhere around 32mm as opposed to 22mm which the OEM shop manual recommends. I assume I should get my pliers and adjust? I will need to check the two remaining bowls to see if this adjustment is common for all four of the carbs. Any clue why they'd be altered as such?

Offline jabar

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Re: '77 CB550F - budget project
« Reply #11 on: March 06, 2012, 09:52:30 pm »
So, after a lengthy pause due to new jobs, moving, winter, being alternatively busy/lazy, I am getting back to the rebuild. I have given the bike a good clean-up and will be taking a different approach. I will be shortly ordering replacement gaskets for the carbs and finally finish them. The gas tank will be tackled soon, not sure if it's salvageable. I've been kicking the engine over and everything seems fine.