1976 CB550 - Holes in pistons save weight, right ?

morepower4me

New Member
Hello,

I've been lurking on the foums a while learning more about vintage bikes, and thought I would finally show-off (modestly) a bit of what I've been up to.

About me:
Never owned a street bike before & this is my 1st bike build outside of dirtbike stuff when I was younger. I have done a lot of car modifying for auto-X and drag racing, so I hope some of that transfers!
This is my 1st 'big' project in the new (1st) house, and lot of the little stuff, like organizing the garage, buying new tools, sorting/storing stuff is slowing the project down & affecting the budget... but it'll get there.

About the bike:
I bought this 1976 CB550F in October last year as a 'winter project'. Being new to Chicago (from Arizona)... I didn't realize quite how cold unheated garages are... and the project quickly moved to a Spring one!
Bike was purchased non-running & I had no idea what to look for. It was dumb luck it is as 'solid' as it is, and even so - its pretty rough!

I finally got started on it & have made a little progress. The early part of this thread is older (a few months) but catches up. I'll be current from here on out.

Bike as it came to me: (you can see it's already marking its spot...)
bike019.jpg


And a few more cell pics showing other angles and the sad condition:
Front.jpg

Engine.jpg

Rear.jpg

Controls.jpg

Rear2.jpg




In the 1st day of wrenching I tackled the most offensive pieces &
Removed Sissy bar
Removed rear fender
Removed rear brake & turn lights
Installed new rear shocks (with reservoirs) from a CB1100F (thanks Ebay)

I also turned the bars down to get an idea of whether I could chop the existing ape bars to save a few bucks... but I could not!

bike017s.jpg


Second day of wrenching was also pretty effective.
Got the rear 16" 'cruiser' wheel switched out for a 18" 'cafe' style one
Removed the very rusty F tank it came with
Removed the rack of carbs & started to clean them up

photo.png


Most recent day of wrenching happened on a weekday.. and was cut short by the next day's impending work. Still knocked out a few items:
Finished Carb rebuild & reinstalled Rack & linkage
Installed the less rusty tank from a 550K (it bolted right on)

tank.jpg


I'd purchased some new parts to create a more modern interpretation of a cafe (USD forks from a 03 GSXR 750, clip-ons, 6 Piston Tokico calipers, dual 320mm rotors) but like most projects... I was running into funding issues and may take a more 'period correct' approach since I can do that for a bit less money.

So in the meantime I decided to get my existing parts working better.

I managed to revive my front brake.

The front Caliper was completely seized and the lines were bone dry, but a friend and I pulled them apart, 'un-stuck'd' the caliper, ground away all the rust on the piston and pad, then put it all back together.

The brake works as it should (piston pushes & retracts) and so far it is holding pressure and fluid. We'll see how long I decided to use that... but at least it functions.

Throttle cables are no good though. The HUGE return spring on the carb rack is still not enough to close the throttle. I need to twist the grip backwards to close it. I'll start it like that, but not thrilled about wanting to ride it like that!

Pulling apart the throttle tube it looks like the tube itself is broken and that may be causing the bind. I'll order a new one and hope for the best, but I think new cables are in my future to ( at a minimum)

Here are those pictures I promised.

Front calipers/lines after reviving them (still need cosmetic help - but at least they work!)
IMG_7141.jpg

IMG_7142.jpg

^^ I can't imagine the 2 sides of the clamp should be discoloring at different rates... but we'll see how they clean up.

Newest side profile - still trying to decide whether to go clubmans (for authenticity) - Superbike bars for comfort - or clipons....
IMG_7140.jpg


And the view from the back
IMG_7147.jpg


These last pics are what I had originally planned to use - but I am starting to think a more 'classic' approach is the right way to go.

IMG_7150.jpg

photo1.jpg


I'd found all the parts necessary to mount the fork (which can be done with some clever steering head bearing changes) - but the machine work to get the spoked wheel spaced correctly in the wider axle, to re-drill the rotors I purchased for the CB hub, and to fab up caliper mounts proved to intimidating.

Looking back, there were other ways documented on the forum I could have & should have gone - but I was chasing deals - and thought I could do it on the cheap. If i had access to a machine shop I likely could have - but paying per hour it can't work. Buy a complete front end if you want to swap, it almost always is cheaper in the end.

And if you can't afford the $600 a whole front end costs... Take it as a reality check - you can't make it work for less than that.

The only upside is that I was able to sell the pieces I purchased to someone else for a few bucks more than I paid. So I only hurt my pride, not my budget.


Lastly...
It Runs!!!
Not well... (throttle needed to be 3/4 open & ONLY 3/4 open) and not for long, but it was 30 or so degrees out with full choke and I was jumping the starter relay with a screwdriver.

I am hoping that the rough running was caused by the lack of any air filters (it was open carb) and any exhaust (also open header) because if not I'm a little stumped. I guess I just expected it to fire up & work... I blame TV.

To be honest, worries over why it wasn't running slowed the progress down a few months & made me question whether or not I had the ability to finish it. For a while I was going to sell it & just get something newer & working...

But I've come to my senses & I'm back on the wagon. Its time to make it work.

I just ordered Uni-Filter pods & clubmans to get things moving again, and I'm REALLY hoping the bike starts and runs a little better.


And to cover some downtime at work...I made this progress (and photoshop) of where I'd like to see it go (+/- a few changes.)

progress.jpg
 
Re: Another CB550 under the knife

Ha nice photoshop, if you were to acutally do the rear to match the tank like thaet it would be great! Dont get discouraged either. Just work your way through it. Take the carbs apart and clean them out, check the timing, make sure your getting spark on all cylenders. eventually you'll be grinning ear to ear and telling anyone who will listen (and some who wont) that you "got that old honda running". Keep it up. This site is a wealth of know how, you just gotta look.
 
Re: Another CB550 under the knife

^^ I'd really like to, but I can't seem to find a paint code or color that matches anywhere... the hunt continues.
 
Re: Another CB550 under the knife

Got the Uni Pods (PK-3 model), the clubmans, and also an adjustable clutch lever from a late 90's ZX6R in the mail the other day - things are looking up.

The outermost pods hit the frame slightly, but since its just foam, the filter gives way a bit & it should work out.

I am hoping I can re-use my existing left controls & just cut the stock clutch perch off & sand/paint... The new lever is long enough to go past the controls so it just might work... but I'm going to fiddle with it & be sure before I hack it up.

Most importantly, now that the filters are in, I can re-start the bike and see if I can get it to run a little better.
 
Re: Another CB550 under the knife

VonYinzer said:
why are you replacing the clutch lever/mount?

2 reasons - the first is that the adjustment nut & lever itself on my bike have a lot of play in them (and replacing those pieces would have cost more than the part I bought). And the 2nd, was I was hoping the adjust-ability & leverage change might help the lever feel. Right now it is super stiff.

I paid $20 shipped, so I don't lose too much if it didn't fix it & I think it looks pretty cool either way.
 

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Re: Another CB550 under the knife

All good man. Just wondering. Its going to be real tough to fit that on clubmans with the stock switch housing though.
 
Re: Another CB550 under the knife

Hmm. Can't say I anticipated that... :(
Do you mean enough width in the bar to fit it all or something else I'm not considering?
I know guys have had trouble fitting stuff with clip-ons, I was hoping I'd be OK. I guess I'll know for sure this weekend!
 
Re: Another CB550 under the knife

You going to throw some drop bars on her?
-Slice
 
Re: Another CB550 under the knife

Slice said:
You going to throw some drop bars on her?
-Slice

Yeah - got my package with Clubmans yesterday. I'm going to run the wiring externally for now. If I ever 'finish' the bike I may re-run them internally, but I have a funny hunch I'm going to be chasing wires/elctrical stuff for a while!
 
Re: Another CB550 under the knife

How bad is the clearance on the frame and pod filters? I wanted to go with the pods but I'm not sure which ones will fit.
 
Re: Another CB550 under the knife

I'll get a pic this weekend. It definitely fits, but the chrome cap gets pushed in slightly.
So instead of looking like this -| | it looks like this -| \
Less severe though.

I may be able to create a few more mm of clearance by playing with the carb boots & the fliters.

If you want Uni's, you have to get the PK-3, not the PK-92, those are too large. I think the Uni's look pretty sharp though, in my opinion nicer than the other non-K&N filters.

I think I paid about $48 here & it shipped pretty quickly - http://www.powersportsuperstore.com/ProductDetails.asp?ProductCode=4184656&CartID=1
 
Re: Another CB550 under the knife

Thanks I'll check that out. Are you changing the exhaust too? I have been reading about having to play with the jet sizes. I just ordered a bunch of different sizes from Dime City Cycles for when I get to that point.
 
Re: Another CB550 under the knife

to avoid chasing wiring ghosts, just check the function at all the wires and clean all the connections as you put them on.


open the switch housings, clean them and regrease them with dielectric grease for protection and run them through their paces, checking continuity and proper function for all of them, then the only surprise will be hooking them up wrong in the headlight bucket!


it would take a long time to sit down and do it all at once but if you do it as you put things back on the bike it will go faster, including in the fuse block, taillight, ect.
 
Re: 1976 CB550 - 1 cylinder not firing - WTF?

Threw the rest of of the Uni filters on & fixed the wiring leading the the start button (PO moved it underneath the gas tank as a theft deterrent (WTF?) and the bike fires up.
It works WAY better using a button instead of jump starting it with a screwdriver... Feels like a real bike now!

Unlike last time, it would kinda/sorta run now, and rev. Overall I felt MUCH better about the condition of the engine & the progress I've made.

However... only 3 pipes got hot.
I pulled the plug on the cold cylinder (plug wire 2) and the plug was wet. I cleaned it & then switched it to cylinder 1 & put cylinder 1's plug into cylinder 2 hoping it could be that easy... but it never is.

So now I need to research what is going on.

I know its getting fuel because my float bowl gaskets are bad and that cylinders carb is leaking gas - so it must be spark.

Anything easy I should check 1st?

Also, is there an easier way to get to the center plugs? I almost removed the gas tank trying to get it in!!
 
Re: 1976 CB550 - 1 cylinder not firing - WTF?

Check you points and make sure they are gapped properly and clean. emphisis on clean.
 
Re: 1976 CB550 - 1 cylinder not firing - WTF?

I just checked that cylinder (#2) for spark & it has it.
WTF

So the plug came out wet, it dumped raw gas out the pipe, and it has spark.
 
Re: 1976 CB550 - 1 cylinder not firing - WTF?

Have you done a compression check?

If you have decent compression, then you could be flooding it out due to carb issues.

If you do not have decent compression, then that's why.
 
Re: 1976 CB550 - 1 cylinder not firing - WTF?

You have spark and you have excess fuel and that is probably the whole issue- that carb and too much fuel.

Stop it leaking and set the float height and check the float valve - it's probably the problem right there.
 
Re: 1976 CB550 - 1 cylinder not firing - WTF?

I think you're right Teaser. Ordering some carb parts and will take a REAL close look at the carb on cylinder #2 when I'm re-rebuilding.

Compression felt OK (and sounded OK starting) but I think I'll check to get some baseline #'s.

Thanks all!
 
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