Author Topic: CB550 top end rebuild  (Read 11505 times)

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Offline Maurice

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CB550 top end rebuild
« on: December 04, 2013, 10:52:36 AM »
Ok, let's try to do this.

I got this here



and this stuff



Notice the lovely longer forks with everything else stock, mostly. No title, so I got a titled frame and swapped the motor, good fork over and got it running with minimal wiring, ignition + charging system plugged.

Got that working, however from looking in the exhaust and intake ports I could see valve seals were in my near future, and sure enough it smokes a bit. That and leaks from a couple places, oil pump and valve cover.

Time to bite the bullet and tear down.

So far here's where I am.

Pulled the breather cover out. Time to play the lottery:



Cover off, what do you guys think of these cam lobes?



What about tappet surfaces?





Keen eyes will notice in the above something to take care of:



New adjuster screws are needed. All valve tips look like these though, which is better in person, they appear intact:



That's where I am right now, this is going to take a while.

Another question: when putting the cover back on, why not undo all adjuster screws so as not to bend the valves? Clearances need checking anyway. Combined with the rubber band trick, would that help prevent bending the valves. I'll try that at any rate, since the screws need to go, and hopefully I get there soon, can't wait to ride this bike it sounds great and is so smooth compared to the twins I'm used to.

Cheers

Offline dave500

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Re: CB550 top end rebuild
« Reply #1 on: December 04, 2013, 11:46:15 AM »
yep back the adjusters right off when you reinstall.

Offline Deltarider

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Re: CB550 top end rebuild
« Reply #2 on: December 04, 2013, 11:57:12 AM »
Cam followers are fine, lobes are hard to judge in that photograph but look OK.
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Offline Maurice

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Re: CB550 top end rebuild
« Reply #3 on: December 04, 2013, 12:10:35 PM »
Thanks for the feedback, guys, yeah not as much light as I'd like in there. During the day I'm stuck at work (arumph... er... taking a little break here...) so I can only wrench with the light of candles and a drippy nose in the non-heated garage.

Tonight I'll pull the head off (sounds gore) and see what it's like. Engine had good compression, apart from needing to restore #2 spark plug hole hopefully I can get away with just a valve re-lap and new gaskets.

Although I've already heli-coiled one of the exhaust studs, that wasn't too bad actually using the flange as a guide for the drill and tap.

Offline Duanob

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Re: CB550 top end rebuild
« Reply #4 on: December 04, 2013, 04:07:10 PM »
Do you have a manual to follow? Beside the head nuts there are a couple smaller bolts holding the head to the jugs that some guys get frustrated and end up prying and breaking fins. Also you might get lucky and not disturb the base (jugs) gaskets but unlikely so be ready for that.

the exhaust studs are pretty common thing to strip. I bought a kit with 6 helicoils with the bit and insert tool. I've used all but two inserts one one bike! Could've been over heated at one point. Something else to keep in mind.

A time-sert might work best for the #2 plug hole. It will be a lot easier to deal with that once the head is off.

get yourself a complete top end gasket kit but I would go OEM on the head gasket. the kit should come with valve seal, pucks, new cover gaskets, all o-rings, copper exhaust rings, intake and valve cap o-rings, base gaskets, etc, etc, etc. Some guys have good luck with the HG in a good quality aftermarket kit like Vesrah. But if it fails because of imperfect fit, you will be going back in to fix it. I used a copper spray and so far no oil leaks at the ends of the head.

Welcome to the board and good luck.
"Just because you flush a boatload of money down the toilet, doesn't make the toilet worth more",  My Stepfather the Unknown Poet

1974 CB360T
1976 CB550K2 Resurrected
1976 CB550F2 Barn Find
1979 CX500 VG "HONDA-GUZZI"
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Offline Maurice

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Re: CB550 top end rebuild
« Reply #5 on: December 04, 2013, 05:34:30 PM »
Yes I follow the Honda manual. Weird stuff in places, the ignition timing setting took me a few reads before I got it. Either that or I'm dense. At any rate at least it shows bolts where they go etc. Coupled with parts diagrams it's all I need to figure this out. I think...

I've got the head off. It came off normal, couple hits (not on the fins) with a rubber mallet, no surprise. Sorry folks, no drama. Yet.

Pistons and cylinder walls look fine to me. The base gasket looks intact, jugs didn't move so I'll leave them be. Inside it was surprisingly clean, the pistons still show metal, I was expecting a layer of carbon. Will post some pics later.

I got the vesrah kit (well, on the way), and I have some copper spray laying around that's a good idea.

Need to clean the things now, there were spider nests everywhere in the nooks and crannies in there.

Should I go ahead and time-sert all spark plug holes while I'm on a roll here?

Offline Maurice

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Re: CB550 top end rebuild
« Reply #6 on: December 05, 2013, 05:50:52 AM »
Head pulled, wasn't that hard, while it didn't exactly fall out it wasn't stuck in there either. A couple whacks with a mallet (not on the fins!) and it moved.

Overall view



The bottom of the valves look like this



Cylinders and pistons





They don't look that dirty. Outside is dirtier still.

#2 plug hole, still holds pressure but it's getting a time-sert, this makes me uncomfortable



My plan is to leave the jugs alone since the base gasket wasn't disturbed and pistons/cylinders look ok (to me at least...). Although to clean them properly outside I'll probably have to wait until the motor is buttoned up I don't want any of it entering the cam chain tunnel.

This whole operation is surprisingly simple. I'm doing all this with motor on the frame. This looks like a toy compared to Jeeps I'm used to working on. To break the head nuts free all I used was a regular 1/4" ratchet, because none of the sockets I have fit the holes. I do need to get a 3/8" 12mm socket to fit on the torque wrench for re-install.

Lots of cleaning in my future, I started doing the inside and carbon deposits come out rather easily with just brake cleaner and a toothbrush. I suspect the outside of the head will be fun with all the hidden cavities... My work's cut out for me.

Cheers

Offline Duanob

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Re: CB550 top end rebuild
« Reply #7 on: December 05, 2013, 04:25:34 PM »
Doesn't look bad at all. the 550 is nice that you can leave the motor in the frame to do head work. Time Serting all 4? Interesting thought. These motors aren't prone to stripping out so I would say don't bother. The PO probably cross threaded the plug and kept going. I had a 97 F150 with the 4.6L V8 that was prone to blowing spark plugs, it was a pretty common problem. I thought if I ever had to take the heads off I would've installed time-serts in all the plug holes. Ford should've offered to do that for free instead of ignoring the wide spread problem. They didn't offer to do that at all they just wanted to put a new engine in it for $5000 at my expense. They lost a fan and customer forever in me.
"Just because you flush a boatload of money down the toilet, doesn't make the toilet worth more",  My Stepfather the Unknown Poet

1974 CB360T
1976 CB550K2 Resurrected
1976 CB550F2 Barn Find
1979 CX500 VG "HONDA-GUZZI"
2007 Moto Guzzi Breva 750ie
2015 BMW F700GS
Another 1976 CB550K Cafe?

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Offline LesterPiglet

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Re: CB550 top end rebuild
« Reply #8 on: December 05, 2013, 04:33:20 PM »
Am I the only one who doesn't posess a torque wrench?
'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Draw and drawer. Could care less/couldn't care less. Bought/brought FFS.


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Offline Maurice

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Re: CB550 top end rebuild
« Reply #9 on: December 05, 2013, 04:53:45 PM »
Am I the only one who doesn't posess a torque wrench?

So long as you stop tightening just before bolts snap and threads strip, you'll be good :D

Offline LesterPiglet

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Re: CB550 top end rebuild
« Reply #10 on: December 05, 2013, 04:56:14 PM »
Always have been. :)
'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Draw and drawer. Could care less/couldn't care less. Bought/brought FFS.


Les Ross.            Certified by a Professional

Offline Maurice

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Re: CB550 top end rebuild
« Reply #11 on: December 05, 2013, 04:58:55 PM »
Ok we'll see how easy the time-sert is, but the other plug holes look perfect so I'll probably leave them alone.

Sorry to hear about your experience with Ford, must have been frustrating. What big corporations wouldn't do for profits...

Offline Maurice

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Re: CB550 top end rebuild
« Reply #12 on: December 08, 2013, 09:34:04 AM »
Well, as expected I am going out of my mind scraping the head gasket off the head and cylinder. Bit less on the cylinder side but still. What a joy. Fortunately the spark plug repair tool and inserts and gasket kit haven't arrived yet.

Offline TheAngryTexan

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Re: CB550 top end rebuild
« Reply #13 on: December 08, 2013, 01:15:34 PM »
I'll be following this.. I just picked up a '78 CB550 that needs the top end rebuilt. I also just joined today. Are you planning on documenting this as much as you can?
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Offline Maurice

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Re: CB550 top end rebuild
« Reply #14 on: December 08, 2013, 02:21:17 PM »
Yes, I'll try and take pictures as I go.

I'm more or less in the following state of gasket cleaning, cylinder side:





Head side, this is what's left:



Getting here was painful, razor blades, gasket remover, old green scotch brite pad, elbow grease and sore fingers. I need a drink now.

Offline becken

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Re: CB550 top end rebuild
« Reply #15 on: December 09, 2013, 05:28:17 AM »
It may be worth your while to drop the oil pan and clean it and oil pump pick-up. Doesn't take very long and is good for peace of mind.
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Offline Maurice

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Re: CB550 top end rebuild
« Reply #16 on: December 09, 2013, 05:58:02 AM »
Thanks, will definitely do. I think I have a new oil pan gasket somewhere already. Is it ok to spray some brake cleaner in there to flush crappy bits out? Compressed air only through the oil passages I assume?

I noticed some rubbing of the cam chain on the cylinder block tunnel walls, near the cam chain guide. Does this happen sometimes? My guess is that the chain ran a bit loose at some point. Will snap a pic.

Offline DustyRags

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Re: CB550 top end rebuild
« Reply #17 on: December 09, 2013, 01:56:36 PM »
OK, here's the fast way to get gaskets off, as taught to me by an old Honda race mechanic: 300 grit sandpaper, laid on a FLAT board. Scrub the head across it. This knocks down all the high spots (gasket), but takes virtually nothing off the flat surfaces because there's so little pressure when the weight of the head is spread out that far.

For the base, I used the side of the board- kept it all nice and flat, and let me get in close to the studs. The bigger the surface area, the better and make sure your lapping surface is FLAT, and you'll be fine.
1976 CB550K- sold
2005 Kawasaki Vulcan 500- sold
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Offline Duanob

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Re: CB550 top end rebuild
« Reply #18 on: December 10, 2013, 01:42:09 PM »

I noticed some rubbing of the cam chain on the cylinder block tunnel walls, near the cam chain guide. Does this happen sometimes? My guess is that the chain ran a bit loose at some point. Will snap a pic.

that is exactly why checking and tightening the cam chain is part of the 3000 mile tune up. They will get sloppy and can do damage. If there is no damage affecting integrity or functionality, I wouldn't worry about it. Just keep the chain tight from here on out.
"Just because you flush a boatload of money down the toilet, doesn't make the toilet worth more",  My Stepfather the Unknown Poet

1974 CB360T
1976 CB550K2 Resurrected
1976 CB550F2 Barn Find
1979 CX500 VG "HONDA-GUZZI"
2007 Moto Guzzi Breva 750ie
2015 BMW F700GS
Another 1976 CB550K Cafe?

  __o
_- \_<,
(*) /' (*)

Offline Maurice

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Re: CB550 top end rebuild
« Reply #19 on: December 11, 2013, 03:28:09 PM »
The cam chain rubbing is as such. Come to think of it, I think it's the chain guide that did that...



Dropped the oil pan, no big bits of chewed up things, very little shavings if at all. Oil screen has some tiny black specks. Checked the primary chain:



This is with chain drooping, seems like there's a bit of room between it and the oil tube:



I'm going to leave this alone now, this is the cylinder block:



The head (no pic) is almost clean of old gasket, but not quite. Was not expecting that, I hope the surface is still straight (checks out ok with the side of a measuring caliper...) I scrubbed it so much my fingers are raw.

Next step (well, after I remove that GD gasket) is to install the spark plug insert, I'll try and document this a bit. Then lap the valves.

Offline Maurice

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Re: CB550 top end rebuild
« Reply #20 on: December 12, 2013, 06:01:18 AM »
Finally



This surface is not entirely nick free (not mine, I could shave a gorilla's ass with an old spoon without waking him up by now), but they seem to leave enough surface for sealing properly.

Offline DustyRags

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Re: CB550 top end rebuild
« Reply #21 on: December 12, 2013, 09:36:34 AM »
Head looks great!

I'm not seeing any wear in the cam chain tunnel- where are you seeing it? You don't mean the cut outs for the cam chain slider, do you?
1976 CB550K- sold
2005 Kawasaki Vulcan 500- sold
2000 CB750 Nighthawk - sold
1975 XL350 - crashed
2004 Suzuki Vstrom 650 - sold

Offline Maurice

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Re: CB550 top end rebuild
« Reply #22 on: December 12, 2013, 10:07:45 AM »
Thanks, let's hope it's still straight...

This is what I'm looking at:



It's really no big deal, looks like the factory paint is barely scuffed, and there's quite a bit of meat at that location as to not be too concerned. Cam chain looks fine too.

I hope I can take some time to lap the valves and replace the seals. Leaving all this junk in pieces is making me nervous of knocking one of the boxes of bolts/small stuff and see them roll under dark recesses of the garage... I plan on doing valves 2 at a time so there's less a risk of that or me just plain confusing #1 and #4. At least exhaust and intake valves can't be mixed :D

It's colder here and I'm probably just a nancy boy but working in the garage is getting tough. And there's still snow out there so no riding either....

Offline DustyRags

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Re: CB550 top end rebuild
« Reply #23 on: December 12, 2013, 10:22:34 AM »
Eh, that's nothing. Here's mine- you can see that 1/4 inch deep furrow on the left there:



And here's how I stored my valves:



Search "glitter in the oil" if you wanna see my top-end rebuild thread from last summer. Lots pics there, and great advice from the experts here.
1976 CB550K- sold
2005 Kawasaki Vulcan 500- sold
2000 CB750 Nighthawk - sold
1975 XL350 - crashed
2004 Suzuki Vstrom 650 - sold

Offline Maurice

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Re: CB550 top end rebuild
« Reply #24 on: December 12, 2013, 10:33:17 AM »
Woah, well I consider myself lucky. For once. BTW in your thread I see that you removed the carbs from the boots, and I find it 100 times easier to unbolt the intake from the head instead. I'm sure there's a huge downside to it, can't be that easy...

Question: how did you ultimately get rid of the varnish? I had to very carefully hold my breath and scrape with a razor and it would just break off...