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1977 CB550 Project

105K views 223 replies 32 participants last post by  flipmotorcycles 
#1 ·
Hey guys,

So as previously mentioned in another thread I picked up a 1977 cb550F last week in reasonable condition. Plan for now is to just get it cleaned up and running well and rideable. I'm self employed and keep my own hours so not really as busy as someone working 5 days a wk w/ a 9-5. Hoping I can move relatively fast w/ the work..only hinderance will be waiting on money to come in to fund the next stage. We'll see though. I've gone ahead and downloaded a honda service manual, parts manual and Haynes' Motorcycle Basics Techbook.

Known issues:
Currently the engine starts and idles but 2 of the throttle slides are seized and the other two were stiff so the bike does not rev up when the throttle is turned. Front brake is not working, needs new battery, and possibly the oil pump is not working? The guy I bought it from suggested there might be an issue since there was a slight ticking when the bike was running.

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Carbs:
Pulled the carbs and have started to disassemble. They weren't gunky but more like dried up crud all over the inside. Right now only one is fully disassembled. The float pin is stuck on the 3 others so I've been dripping berrymans carb dip on the pin periodically over the past day and a half to loosen. Was able to get the 1st out this way. Would just soak em but didn't want to fuck up the floats. . Once i get the pins out I'll see about unsticking the two throttle slides that are stuck. there's a few marks from someone trying to pry them up w/ a screwdriver already. I've been dripping some berrymans on the slides as well to see if that helps unstick. will probably try messing w/ later today.

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Auto part Carburetor


Should I be concerned w/ this mark on the throttle slide? Is it indicative of anything?

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Gas Tank:
Tank is rusty inside..PO had fresh gas when i went to pick up so i drained to see how much rust was in there....brown gas came out of course(see pic below). Thought I would just see rust and silver metal on the inner tank body after it was empty but there's also some type of black in there that is flaking. Am I right to assume it might have been lined in the past w/ Kreem or something similar? If so, I would like to get that shit out before I redo inside of tank but, I have researched what to use yet. However, I did do some research for rust removal and phosphoric acid seems most appealing method to me. also supposedly leaves a zinc coating???? but i haven't been able to confirm that anywhere.. thoughts????? I would prefer not to use a sealer if i can avoid it. Just don't like the idea of having something in there beyond what's needed that might fail.

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Other Things:
Have read through a few project threads on here and really like what Dean has been doing w/ the rust removal and zinc plating all the bolts/screws and metal. Wondering if instead of the plating kit i can accomplish the same by dipping in phosphoric acid since it supposedly leaves the zinc coating? If not then I'll just buy the kit. Regardless, I think I'd like to clean up as I go.

Even though the engine runs I'm thinking I should open it up and check everything out/clean up in there as well. figure if i'm going to clean the carbs and all the other bs I should do the engine as well and i'd also like to know nothing major is wrong that's gonna kill me once it's rideable. Yay or Nay?

That's about all I've got so far. Once I've got the carbs clean and the tank redone will move onto the next step.Thoughts on what it should be? Any other thoughts welcome as well.
 
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#3 ·
Unlikely that the oil pump is not working - ticking sounds are probably tappets (it would sound REALLY bad if there's no oil getting to the top end).

And as muskie says get the carbs cleaned up and the engine serviced before you go "pulling it apart" like an over-zealous newbie - or else you'll end up with half a garage full of parts that was once a motorcycle.

For the tank, get a handful of nuts / washers and loop them all together on a piece of string. Then drop that into the tank with some kerosene and shake the shit out of it. Most of the black crap should come away with that - if there's heavy rust / pitting you can try electrolosis, but it's probably not necessary (just make sure you have a decent paper fuel filter to catch any crud before it gets to the carb bowls again).
 
#4 ·
Phosphoric acid doesn't leave a zinc coating. It just dissolves rust.

That photo you posted shows very little rust inside the tank. If the rest of the tank looks like that, you probably will not need to use with phosphoric acid. Do what Hillsy said, and then use a flashlight and a small mirror and look carefully all around inside. You want to keep doing the nuts-washers-kerosene treatment until the tank is totally clean.

If you see severe rust patches even after you do the nuts-washers-kerosene treatment, let us know. Then we can discuss a three-step process including phosphoric acid, primer and epoxy coating, such as POR-15.
 
#5 ·
Have read through a few project threads on here and really like what Dean has been doing w/ the rust removal and zinc plating all the bolts/screws and metal. Wondering if instead of the plating kit i can accomplish the same by dipping in phosphoric acid since it supposedly leaves the zinc coating? .

bfont52, Steve is right about phosphoric acid. What you are thinking of is the eastwood "after blast" solution I use to clean and protect freshly blasted or stripped metal prior to paint work or plating. It has phosphoric acid to clean and etch the metal and ALSO zinc phosphate to leave a coating to protect against flash rust. It is the non-visable flash rust that compromises plating results and primer adhesion so it's handy stuff as a prep, however it is not a long term protective coating.
 
#7 ·
Have a few updates. nothing really exciting though.

adjusted the tappets and points.

rest of the gas tank was definitely rustier than that top portion. hit it w/ drywall screws, then some vinegar for a couple days to get the large stuff out. tried phosphoric acid after that to close it out but it kept flash rusting even after trying to give it a little coating w/ some 2 stroke premix. so i'm doing the vinegar again and gonna leave it after that. been cleaning up all my rusty bolts w/ the vinegar as well...working pretty good. not as pretty as dean's zinc plating though. :)

cleaned up the carbs/cleared passages...o-rings all seem to be in good shape so keeping those. ran into an issue w/ carb #4, slide will just not come out so looking into replacement...think i found a guy on sohc4 forum w/ one.

disassembled master cylinder, no brake fluid anywhere in the lines. plenty of rusty water though :). piston completely corroded...found a replacement MC from David Silver for $50. anyone have experience w/ or other recommends? took off the caliper as well but haven't cracked it open yet to see how bad that is.


Suspension:
what do you recommend? i've seen a lot of bad mouthing of progressive shocks on here. what's a good mid-range shock? bike is intended for around town and highway. i'd like to put some decent money into suspension and tires.

brakes:
Do I need ss lines??? I see all this business about panic braking and higher potential of locking the front wheel w/ ss lines. should i be weary?

my airbox is missing the top duct, any idea how much of an effect that's going to have? there's one on ebay right now for $25 so thinking i should just grab it but, i'm also missing the piece between the box and the duct.

that's about it. what should i look at next engine wise once i get the carbs back on? planning to do ignition timing but, anything else?
 
#11 ·
brakes:
Do I need ss lines??? I see all this business about panic braking and higher potential of locking the front wheel w/ ss lines. should i be weary?
I know a thing or two about brake hoses ;)

Locking up the front wheel isn't a result of going to stainless braided hoses. To be completely honest, you would have to be pretty sensitive to notice the difference from NEW rubber hoses versus stainless braided on this bike. The only dynamic difference would be in the amount the hoses swelled up from the pressure you generate with that master cyl (which isn't much at all).
My rubber hoses would be a stark improvement over 40 year old hoses. My braided hoses would be even more of an improvement but truth is most people don't actually need them on these old street bikes. Race bikes, that's a different story.
Stainless definitely look better. (esp my Gen II hoses)
But if i find out you purchase another brand of hoses, i will track you down and make you try mine instead!
 
#8 ·
I just paid $50 for a very good condition but used master cylinder from my local salvage yard. The CB550 uses the same front brake system as the CB450 & 500T, the CB500 four and I'm sure others so look around. Rebuild caliper and master, new pads, stainless lines and make sure the rotor isn't glazed. The old single piston caliper on these heavy ass bikes doesn't do much but these affordable upgrades will help a ton.
 
#9 ·
Contrary to the ignorant opinions bandied about on here, Progressive Suspension rear shocks work just fine. I have a set on my Seca 550 racebike. They will not be the weak link in the handling of a CB550F. The front forks will be. The noise is not the oil pump. It is either a valve or the timing chain, all of which can be adjusted unless the engine was run without oil in which case it could be the cam bearing surfaces are shot. That would be bad and also the least likely.
 
#10 ·
Progressive shocks are fine. I do prefer the Hagons though, specifically the 2810's. Preload and 10 position damping adjustment, with spring setup from hagon for your bike/weight/use.
Ken is 150% correct about the front end.
 
#14 ·
finally got this thing started up yesterday. started up pretty quick. (see video). would be curious if anyone has any thoughts about this sound.







things i've done so far
cleaned carbs and set float level.
made tappet adjustments
adjusted points gap.


still to do:
adjust cam chain
ignition timing
compression check
change oil filter, oil, and clean screen (PO put fresh oil right before he sold to me but going to swap again.)
get new spark plugs

anything else I should look into?

also found a snapped bolt on the top engine cover. woohoo.
 
#17 ·
has spark. also tried swapping spark plug w/ #4 and #3 still won't fire....plug from #3 did fire in #4 though. i need new plugs anyway but it's mardi gras here and i'm blocked by parades until later.

also peeked in through the spark plug hole. looks like a lot of carbon build up on top of piston head.

also swapped the wires between #3 and #4. still nothing on 3.

#4 seems to not be running either now though.
 
#18 ·
Swapping the wires for 3 and 4 will make neither 3 or 4 run, since the wasted spark is paired 1and 4, 2 and 3.

Put them back correctly.

If you have spark on 3 and it won't fire, you have a few things it could be: compression, valve clearances, carb. Compression can be low for a few reasons. Valve seats, worn rings, valve clearance, hole in piston.
Do you have a timing light? Make sure it's actually sparking while installed with a timing light. If compression is good, valve clearances are good, and you're sure you have spark, then it's more than likely a carb issue.
 
#19 ·
figured i shoulda swapped 2 & 3 instead. was being lazy though...just tried wire from #3 in #2. works fine. couldn't get #2 wire to reach #3. #4 is not firing period now either. do you think the sound in video is related to all of this or something else.

no timing light or compression gauge yet. on the list of things i need.

appreciate the help.
 
#20 ·
Replace plugs (all of them) and try again.
Get a cheap timing light, borrow a compression tester, and find out if those are happening correctly.

If so,

carb.
 
#21 ·
and so the saga continues....

no one around here seems to have ngk's that are on my bike so I'm still using the old ones b/c all the alternatives I found don't have the 18mm nut so I can't use the honda spark plug socket i have.

picked up the compression tester. results seem inconsistent though.....ran it yesterday on bike while cold and result was 120/150/90/100 i think?? i can't remember....put a lil oil in each after and they all jumped up about 20psi...then after some more reading on sohc4 forum realized i probably should have measured and put exact amount in each one. anyways, today i started the bike again and now #3 is only one not firing. ran it a few minutes, did another compression test. results today are 110/100/90/110. so more even but still low. also, today, the bike is burning a bit of oil.

other things, looks like there's a little bit of oil leaking from #3 near the exhaust header. while i was kicking during compression test, heard a clicking noise that sounded similar to what's going on in the video though only a few times. wasn't doing it the whole time.

am i gonna have to open this thing up?
 
#24 ·
just realized you are in new orleans. Is clancy's cycle still open on the westbank (in Harvey on destrehan ave I think) ? If so you need to go there weekly. That man will a) have all the parts you need or know where to get them, b) will be pretty good about giving you knoweldge.
 
#25 ·
word. thanks Geeto67...i know there's a shop on the westbank. not sure if it's clancy's though. there's a place around the corner called FXmotorsports from my house everyone tells me is good as well just haven't been in yet to check it out.

just ran the bike again....looks like #3 is firing now. hot to the touch but not as hot as the others. noise is still there sounds like it's maybe coming from#3. still burning oil.
 
#26 ·
actually there like 3 or 4 shops on the west bank, but Clancy's is the only one I would consider when dealing with an old honda. More a salvage yard than a real shop, and tons of SOHC honda stuff. I bought many a bike from clancy and he is good people. Still have his number in my phone as 341 6100. He used to have acres of bikes but the parish made him clean it up outside, but he still has 3 warehouse buildings full. A better old bike resource in NO you aren't gonna find.

Also go talk to max over at the transportation revolution (aka the triumph dealer). Ask him about old bike connections in NO, he might know someone to ask. If this was the old days I would send you to Alan Maiver but his shop has been closed for near 10 years now.
 
#27 ·
Thats pretty low compression across the board, but 3 is really low.

Were I you, I would probably do a top end rebuild. Sounds like It was rode hard.
 
#28 ·
Compression numbers aint too bad............................................when you forget to open throttle :D
 
#30 ·
small update. got the head disassembled. would be curious if anyone thinks anything looks excessively worn.

pistons are secure in the cylinders. no movement side to side. cylinder walls feel smooth. fingernail doesn't catch on any grooves. everything seems to be lubricated.

valves for #3 seem to be wet or have some light sheen on them of some sort. also inside the intake port was wet while all the others were dry. wondering if there's not a leak there.

















---someone cut holes in the head cover?????



















 
#31 · (Edited)
Also check your valves before doing the compression test.

Edit: I missed a page, you've yanked the top end.

Ok.

So now you're here a couple of things.

Don't worry about those 'holes' that someone has cut in. A guy at Honda did that after they cast the thing.

You won't know how work that cam is until you pull it out and measure run out with the correct gauge.

On the CB500/550/4 the head itself serves as a plain bearing. Once you have pulled the cam check for scoring. Run your finger nail across the plain surface and if it catches on any marks, you should be looking for another head.

Replace all rubbers and gaskets obviously.

Do yourself a favor and while you're in there replace the tensioner blades. I'd also replace the cam chain. How many miles on the thing? You can split it with a chain splitter and a grinder, make sure the top end is covered well. To install a new cam chain you will need the replacement and a rivetable master link from a shop like David Silver spares, and of course the riveting tool.

Clean up your head and valves. That carbon build up isn't helping. Top's of your pistons too. Looks like your valves can't seal properly.
 
#32 ·
Thanks. For sure. planning to clean all that stuff up.

Here's what I'm wondering though...someone on sohc4 forum suggested I might have an oil problem..said there should be oil squirting out those 2 holes on the side where the lefthand cover is missing in the video and since there wasn't something is amiss. nothing inside seems starved for oil though...

i guess i'm wondering if i clean everything up, make sure the valves are sealing, everything is within tolerance, etc., etc... how do i really know i've fixed the issue prior to getting it back on the bike. bench test i guess?
 
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