Topic: 1978 CB550 K4 Been sitting a while

[BigAl]

I think I will upgrade to an electronic ignition as well.  As for the front forks, I'm not sure what to do with them yet.  Do I just clean them up, replace the seals, change the oil, call it good?  Do I run an emulator and keep the vintage look of the forks?  Upgrade to a set off of something new?  As I find myself leaning to the original equipment, I think I like the look of the originals. 

Here is a shot of the tank and seat.  One of these days I will have to start cutting the frame down for a bar.

[BigAl]

Clutch is done as well.

Feels a bit tight.  maybe just because the clutch plates are new?

[Stev-o]

The tank and seat look good together

[BigAl]

Thanks Steve-o.  I had never planned on a tank of that shape, but it's growing on me.  I have no idea what I'm doing when it comes to fitment.  The tank feels like it sits too far forward, as if the little ears that receive the rubber mounts are farther back than on the stock tank.  The new tank is also a hair narrower at the mounting points so I may have to trim the two metal posts back, not much, maybe 1/8" apiece and then trim a bit off of the rubber.  But, if the tank sits too far forward, I am probably better off cutting them off and welding them wherever they need to be.  Haven't figured out exactly how to measure this all out yet.  And if the tank slides back a bit, the fixture at the front of the seat may need to move back (and consequently move the whole seat back). 

And then cutting off the big hunk of metal that sticks out past the back of the rear shock mounts.  And weld a bar in?  Integrated brake and turn light?  Weld in something squared off and make some blinker mount points?  A lot of compounding options.  And I have never fit a tank / seat on a bike that it didn't belong on.  I certainly didn't expect a "universal" tank and seat to just magically fit, I am just not sure where to start.

[BigAl]

calj737, to be honest I would jump at the opportunity to have the original (or originalish) tank back on the bike. I was disappointed when the tank that was on the bike started to bleed gas out of the Honda emblems.  It had rusted through over the years.

[Gurp]

Post in the wanted section I'm sure someone has a good tank laying around.
I have 1 black one spare still when I go out to the building I'll look to see what kinda shape it's in. I remember it came off a 74 550 I bought for the motor.

[HondaMan]

A word of caution: for all-electronic ignitions, there is only 1 type out there (unless you live in England and can find an old Boyer unit there) that won't kill the bike's electrics. Don't even consider the Dyna S type: that one will ensure you can't ride the bike anywhere but the interstate, lest your battery go dead while riding to Wendy's.

If the points are still working, you can use one of my Transistor Ignitions, which were designed expressly for this bike (by me), circa 1972. PM me for details if interested.

[BigAl]

HondaMan, I must admit I'm intrigued.  I did plan to run one of the dyna kits.  The vast majority of my wrenching and knuckle busting has been automotive, although I have had, maintained, and "messed with" motorcycles my whole life.  Power supply for electronic ignition is not something that was even on my radar as I perused the kits on the interwebs. 

[BigAl]

Well, I have confirmed that I am indeed an idiot. 

As I initially disassembled my CB550 with visions of pod filters dancing in my head, I very haphazardly tossed the air filter housing parts and hardware into a box that contained a bunch of stuff (both from the CB and my VTX, and several other projects that are ongoing).  I also didn't take any pictures.  Typically, I like to take a million or so pictures from every conceivable angle if I plan to put something back together again.  I also didn't pay any attention to how it fit together....

So, I checked out the CB550K4 parts list conveniently made available on this forum and think I have it back together again.  I have managed to lose one of the little brass collars that sits between the housing and intake to the carbs (where the bolt goes through).  I think I can find something that will work.  I also see that the foam "element" that sits below the actual filter sandwiched between two metal contraptions is toast.  Actually it is now in powder form as it crumbled in my fingers.  Any suggestions on a replacement "element"?  Surely I can find something at Napa that will work, oil resistant I'm assuming.  One hose comes from the engine, the other is a vent I think.

That whole contraption that sits below the filter is for environmentally friendly crank case venting?  Everyone keep that stuff as is?

[BigAl]

Ha!  Look what I found hiding out underneath the air compressor!

[BenelliSEI]

Cut a green “Scotch Brite” pad to fit. I soaked in a bit of K&N filter oil and it lasted forever.

[BigAl]

Since deciding to run the stock airbox instead of pod filters, I have resurrected all of the bits and pieces and re-installed them.  I have also readjusted my carbs by going back to the 90 main jet and 1.5 turns of the pilot screw.  My needles are still enriched by one notch, we will see how that goes.  Ultimately I will run a 4 into 1 exhaust which will change the stock dynamics, not sure if enriched needles will help that change or make it worse.

At least I found all of my stock airbox parts!

[BigAl]

The front brakes were a mess.  Full of brown jelly.  I cleaned the caliper up as well as the master cylinder and ordered new braided lines.  With the lines came new banjo bolts.  They look great; black aluminum and a bit fancy, but they are super short.  So short, in fact, that I worry a little about achieving proper engagement.  I think I will sacrifice these new fancy bolts for the longer stock bolts that I took off the bike. 

[BigAl]

Front brakes are buttoned up less the master cylinder repair kit.  It's taking a while to get here evidently.  I ended up cleaning up the old banjo bolts and using them instead of the bolts that came with the brake line kit.  All and all, no real surprises, it installed well.  Things get a little tight around the brake line pressure fitting, but not bad at all.

[BigAl]

Green scrubby makes complete sense to me, but I couldn't help myself.

[BenelliSEI]

If that’s hardware store AC air filter material, I tried some. Didn’t last long.

[BigAl]

I hunted down some 1/4" high density, open cell, polyurethane foam that was supposed to be for like camera storage or customizing a pelican case.  I think it's the real deal (it had better be for the price!).  I had to buy much more than I intended to get my little square.  I'm happy to send you my second sheet if you want to check it out.

I soaked it in ATF before I installed it.  Should have good oil resistivity.

[BenelliSEI]

That sounds great! I’m OK with what I have. Thanks!

[BigAl]

Maybe I'm getting senile in my old age, or maybe I am just experiencing some unforeseen nostalgia, but the more I dig into this bike and poke around this forum, the more I have this inclination to restore the CB550K4 instead of modifying it into a pseudo cafe racer.  There are some absolutely gorgeous unmodified examples of 70's Hondas floating around this board.

I make this mistake with every project.  I get excited, order a bunch of parts that I think I want in order to achieve my perceived end state, and then things slowly change as the work progresses.  No different here.  Racer tank, racer seat, racer bars, haven't dropped the cash on the exhaust yet, but there is definitely an appeal to the original.

I don't know.  Maybe I should rod the 550 out and restore a 750......

Indecisiveness, the bane of my existence (and bank account, and cross-wise looks from my wife with every box that shows up).

[BenelliSEI]

Al…… No question what my preference is, but you should build whatever makes YOU smile!

[BigAl]

Ouch.... poke me where it hurts!  Those are beautiful bikes...

Looks just like mine would have back in 1978.

[BenelliSEI]

That 550K was my first SOHC Honda (my wife had a 400F at the same time). I still have cb750K7 and K8….. sold the 550 10 years ago.

[BigAl]

Finally received my master cylinder rebuild kit.  I paid little attention to the parts I pulled out and have been trying to make sure that I put the rebuild kit back together correctly in the master cylinder.  The parts diagrams are a bit fuzzy, but I did happen to find the old one during in the pile of parts on my workbench. 

Question, is the old one I pulled out correctly configured?  The main rubber plunger?  I think I can figure the rest out, just don't want to put anything on backwards...

That should button up the front brakes.  Reading through the manual, I need to pull the replacement pads and apply some grease around the edges and backs.

[BigAl]

Master cylinder is back together.  I went to install the handle and noticed it was dirty so I gave it a scrubbing and set it out to dry.  With that I can fill with Dot3 and see if everything is tight.

I feel kind of like a dumbass.  As I was looking at the parts exploded view I was thinking that what it showed made no sense at all.  Why would the two rubber pieces be back to back.  Then I found my old piston? plunger? and shook my head a little bit and put it together.  I often find myself doing something, thinking that it just does not make sense, doing it anyway, and then realizing that if I had just listened to that little voice in my head I would have been alright.

Oh well.  It's back together, the snap ring was a pain but not too much of one.

[BigAl]

Well, after no luck with anything of note happening in my rebuilt master cylinder, I read through the threads a bit.  First mistake was to no clean out the little divot forward of the main opening in the reservoir.  I did clean it, just not enough to open the apparently little tiny orifice at the bottom of the divot.  I questioned the feature as I cleaned it and thought that I would be able to spot SOMETHING looking down the shiny barrel of the mc.  So that needs routed out with a guitar string.  I need to restring mine anyway, so I guess that's a sign.  Second mistake was to not really read any advice on priming, filling, etc.  Several methods seem to work, so I'll try a few.  I have some tools that may help floating around in the basement somewhere.