Topic: 1976 CB550K - Project Bike - Dummy and the Art of Motorcycle Maintenance

[duveybearson]

Hey All,

I'm a new member of the forum but a long time lurker. So I've always wanted a classic looking cafe style bike, and more importantly I've always had this desire to work on, maintain and repair an older motorcycle; I blame it on that book Zen and the Art of Motorcycle Maintenance. About 3 years ago I took the Motorcycle Safety Course and decided that my first bike would be all about getting comfortable with operating a motorcycle, it wouldn't be "THE BIKE", it was just my first step towards the dream. So after doing a stupid amount of research on a reliable, not underpowered motorcycle, with straightforward power delivery, I picked up a Yamaha FZ-07. It was a solid first bike with no issues during my ownership, however, it never really fit the mental image I had about the type of bike I'd be riding.

My wife and I recently found out that we are having our first kid so I decided to sell the FZ-07 to have more of a financial cushion for when the baby arrives. My wife, being the amazing women she is, did not want me to sell the bike (even though she worries about me) because we don't really need the money and she knows how much I love riding. I decided on another course of action, I decided that it was time for me to find "THE BIKE". I'm essentially a weekend only rider, since I don't like to ride my bike stressed out and my job requires me to hop around town for lots of appointments. I figured now would be a good time to get a bike that was rideable, needs some TLC, but could be slowly modded up over the course of the next few years. So I sold the FZ-07 (which kept its value really well) and after doing a lot of research on the type of older bike I wanted, bought a running 1976 CB550K.

I've never done any of my own motorcycle maintenance (other than some simple stuff on an old honda moped I had as a kid) and I am coming at all of this with eyes wide open. I'm pretty mechanically inclined and love to get my hands dirty to fix things myself (usually with youtube support), but I know this forum is going to be an invaluable resource for me moving forward. I am ready, willing and able to take any advice or tips for anyone who's willing to share.

Here are the things that I know need to be addressed and what I plan to do:

- there is no tool tray under the seat which acts as the cover of the air filter - no idea what to do, maybe fabricate something simple;
- the air filter is missing the clip which holds it close to the box - another forum member already suggested a 1/2' socket strip in it's place;
- the mirrors don't match - going to at some point put bar end mirrors on the handlebars, it may require new handlebars;
- the seat has a tear - ordered a new Texavina seat;
- side covers are cracked - ordered replacements which I'll repaint;
- PO put a 4 into 1 muffler on the exhaust (in black) welded onto the pipes - I'm a bit annoyed that he welded this to the pipes since I kind of liked the 2 exhausts on the stock bike and the black muffler doesn't match the pipes. I'm thinking of either wrapping the pipes in black so they match or getting a whole new set of pipes. I'm not comfortable cutting above the weld and hoping a slip on will still fit;
-pretty sure PO didn't adjust the carbs for the exhaust change - I'm going to increase main jet size in carbs 1 size as part of overall carb rebuild;
- carbs are leaking gas - I am hoping this is just due to a worn gasket but since I don't know what has been done on this bike I purchased a carb rebuild kit with new floats just in case. I also purchased some spare fuel line in case the problem is elsewhere;
- clutch cable looks like it is rusting and wearing out a bit - bought replacement clutch and throttle cable set;
- I plan on removing the crash bars which were installed;
- I'm going to clean out the gas tank with some evaporust and probably going to repaint it dark green;
- at some point I'm going to replace the gauges;
- finally I bought stuff to change the oil since I have no idea when it was last done.

I'm sure as I get going on this project more things will crop up but I'm looking forward to getting into it this weekend. Wish me luck. I'll keep you all updated.
 

[LastChancer88]

Looks like a nice bike!  I just finished reading Zen and the Art... myself.  There's something about these old bikes man.  Somethin' 'bout 'em.

Have you seen where the carbs are leaking from?  Is it between the bowls and carb body or is it out the overflow tubes?  Those are two very different issues depending on where it comes from.  Might have some stuck floats/bad needles. 

I have personally read a lot about jetting recently and would suggest that you may not have to rejet for just the exhaust change depending on its flow.  I'm sure the veterans here have a better idea on that though. 

Dark green is a good color.  I would +1 that idea.

[FourUsTry]

Nice 550. Should be a fun "hide in the garage while the baby is crying" project  . A few ideas from my own 550 refresh...

Pull up the fork gaiters and check for rust and seal leakage. If no leakage then clean and polish/wax the fork tubes and then flush/fill with fresh fork oil. If the seals are leaking you are in for a bigger job but you can defer it for a while if the leakage is slow.

Stock shocks are not great. At some point maybe you can dip into junior's college fund to get something better.

Flush and refill/bleed front brake with fresh DOT4 or DOT5.1. Check the 2nd hole at the bottom of the reservoir is open for a thin needle to get through. With this age bike you should assume the master cylinder and caliper may never have been rebuilt and even if it is working well schedule that job for next winter (safety first!).


Make sure rear brake is working and adjusted and wear indicator says they have some miles left on them.

Check chain/sprocket wear. If/when you change them replace the sprocket and shifter oil seals. All seals/rubber should be considered worn out on a bike of this age.

Swingarm bushings are not well designed on these machines. Check for any side movement at rear wheel when it's on the center stand. If OK for now give it some grease at the fittings and consider doing a bronze bushing conversion next winter.

Another winter project: wheel bearings: replace with good quality (SKF, FAG, ...) bearings or at least (if they have no slop and rotate smoothly) pop the seals and clean/repack them.

All the cables should be considered suspect and, if possible, replaced with Honda OEM cables for the best safety/life.

The EvapoRust works well but if there is any oily sludge or other non-rust residue in there maybe rinse with lacquer thinner or something of that sort first: EvapoRust doesn't cut through that stuff. Also, putting in some nuts or bolts or some such and shaking it around with the EvapoRust will help scrape off the thicker rust and any gunk. Count the nuts/bolts and make sure you get them all out.

Carbs: Could leave bowls filled with Seafoam overnight to maybe help clean 'em up. The leaking may stop on its own after you leave the bowls full of fuel for a night -- that's what happened to me. You can also try tapping the carbs/bowls with the back of a screwdriver in case a float needle is stuck. If none of that stops the leaking you could do the clear tube float level check but most likely you will at least need to pull the bowls of any that leak and clean up or swap out the float needles. You may just want to do the full carb rebuild at that point.

Have fun. Ride safe!

[flatlander]

welcome!
it looks like you found a good base with that bike. these 550s are nice to work on and great to ride.

make sure you download a copy of the original honda manual for the bike and, before anything else, do the 3k miles maintenance procedure. that will give you a base tune from which you can go and see what else may be needed.

- there is no tool tray under the seat which acts as the cover of the air filter - no idea what to do, maybe fabricate something simple;
many people ditch the airbox and mount pods. post in the wanted section and keep checking ebay, there's a fair chance that a cover (or complete airbox) turns up sooner or later.

- the air filter is missing the clip which holds it close to the box - another forum member already suggested a 1/2' socket strip in it's place;
it's really nothing special, just a bent piece of steel putting some pressure against the filter. you can replace it with anything that works (old sock springs to mind  )


- PO put a 4 into 1 muffler on the exhaust (in black) welded onto the pipes - I'm a bit annoyed that he welded this to the pipes since I kind of liked the 2 exhausts on the stock bike and the black muffler doesn't match the pipes. I'm thinking of either wrapping the pipes in black so they match or getting a whole new set of pipes. I'm not comfortable cutting above the weld and hoping a slip on will still fit;
i don't like the look of that muffler. seems like a dirty hack job and i would just replace it, but that's only personal opinion. original ones are hard to find in good condition and can be pricey. there are a few decent aftermarket ones around. delkevic is not expensive.

-pretty sure PO didn't adjust the carbs for the exhaust change - I'm going to increase main jet size in carbs 1 size as part of overall carb rebuild;
before just guessing on parts to replace, why not get it tuned up (3k maintenance!) first and then check how it performs? if you have issues then, people here can help you identify how to adjust the carb settings, if needed.

- carbs are leaking gas - I am hoping this is just due to a worn gasket but since I don't know what has been done on this bike I purchased a carb rebuild kit with new floats just in case. I also purchased some spare fuel line in case the problem is elsewhere;
you can use the gaskets etc. in the kit but stay away from the brass parts, they won't be the same as the original keihin ones and almost certainly will give you tuning issues. the float rarely needs replacement. the float needles and/or their seats may be worn and if they need replacement, it's best to use original keihin material.
but before doing so... do you know where the carbs are leaking from, and why? do that 3k tune-up, ride bike a bit (if it's in a safe and rideable state). if there's still a problem, locate it, give a description and post some pics and we can help you.

- finally I bought stuff to change the oil since I have no idea when it was last done.
good idea but don't stop there - do the full 3k maintenance (but i'm repeating myself).

[Bankerdanny]

Welcome

Flatlander covered most of the good stuff, I will add that when you buy the carb gasket kit get one with the molded float bowl O-ring rather than just a round one. The non-molded kind can be a major pain in the ass to keep in place while putting the bowls back on.

The bike originally would have had 4 mufflers, 2 on each side. I am also a fan of the original style, but they are pricey, even when used. MAC sells a twin muffler setup that uses the stock pipes feeding into one muffler on each side, which I think looks very good.

I've had 2 550's and they are really fun little bikes with enough power to get you out of trouble, but not enough to get you into it.

[duveybearson]

Thank you everyone for giving me such good tips. No pictures today but I do have some updates.

I pulled the tank and cleaned her out, then replaced the rubber stoppers since they were falling apart. Pulled the carbs off the bike and bought the HTMR video on disassembly and rebuild. I rebuilt the carbs with one of the ultimate rebuild kits from 4into1. It was a bit nerve racking seeing all of those parts splayed out but I got it all back together and on the bike again. I am hoping I don't have to do that again in the near future but based on my new issues below I have a feeling I don't have a choice. I changed the oil and filters, fresh battery (since the one it came with died) and took it out yesterday for a little spin.

Right off the bat I noticed that the bike sounds a lot better than it did before these changes, however, I have noticed that the bike is having issues going from idle to first, it doesn't seem to be getting enough fuel at idle as I am constantly having to feather the throttle to stop it from stalling. It also feels like when I'm in gear it wants more and more gas from the throttle to keep things moving. Is it possible I will need to increase the size on both jets? The bike has a 4 into 1 exhaust and is currently set up with the stock sizing on jets.

Finally, I noticed that there is a bit of a squeal coming from the front end when pushing the bike around in neutral; is it possible that brake fuel change will fix?

[LastChancer88]

I noticed that there is a bit of a squeal coming from the front end when pushing the bike around in neutral; is it possible that brake fuel change will fix?
Front brake calipers sound like they might need to be cleaned.  I've read that the calipers can get gummed up and the piston won't move freely to retract the brake pads fully (or something like that).  My bike also has this issue currently.  There's plenty of youtube vids on cleaning them (hackaweek!)

however, I have noticed that the bike is having issues going from idle to first, it doesn't seem to be getting enough fuel at idle as I am constantly having to feather the throttle to stop it from stalling. It also feels like when I'm in gear it wants more and more gas
I would definitely suggest the 3k mile tune-up.  That will eliminate a few factors from guessing what could be wrong.  Timing and contact points, valve tappet clearances, spark plug color and then dive into the carb adjusting if all that is correct and you're having issues.  It seems a little intimidating but the manual will walk you through it and the tools are all common enough to buy in local stores.  12V test light and feeler gauges are the two I'm thinking someone may not always have.