Author Topic: CB550 top end rebuild  (Read 11506 times)

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Offline DustyRags

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Re: CB550 top end rebuild
« Reply #50 on: December 19, 2013, 09:33:55 AM »
Nice! Looks like you got that tensioner dropped in correctly- I had huge trouble with that, took me days to sort it out. Good on 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 #51 on: December 19, 2013, 09:39:55 AM »
Helps that I didn't remove it :D

From what I understand it only comes out by lifting the jugs a bit, and since that wasn't disturbed I just inspected and left it. Tensioner screw is not stuck, head came up with minimal effort. Hopefully this all holds for a while...

Offline DustyRags

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Re: CB550 top end rebuild
« Reply #52 on: December 19, 2013, 09:48:08 AM »
Excellent! :)

One thing to think about- mine had a stripped lock screw (that's why I had to get in there in the first place) and I later figured out it was because the nut locked up against the end of the threads, NOT agains the jugs. The result was that you couldn't torque that bastard down tight enough to stop it from spinning, because you were just torquing against the screw itself. Once I threw a washer in there, that solved it. So if you have that problem, just put a washer in there. It shouldn't need much torque to hold it in place at all.
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 #53 on: December 19, 2013, 09:53:35 AM »
Ooo good point.

The parts diagram does call for aluminum washers on both screws. I'm pretty sure both are still there, in fact the top washer is just glued to the head with the pain (not sure if it's OEM paint to be honest). But thanks for mentioning, I'll double-check that area. A few of the valve adjuster screws were pitted and there is chain rub which indicates either too tight valves or neglect of cam chain tension adjustment. Or both.

Thanks!

Offline rb550four

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Re: CB550 top end rebuild
« Reply #54 on: December 19, 2013, 01:55:37 PM »
Maurice, still looking good... Easier method of putting on the head washers and bolts....
long Phillips head screwdriver and a flashlight. slide the washer up the shaft to the handle, hold there, put the point on the center of the threads, and drop the washer. use flashlight to be sure it's where you want it.
Bolts, same way,  just be sure they are sitting level , chase the bolt down with a socket on a 6 inch extention  turn by hand so you know it isn't cross threaded. get em all on and torque them. Makes life easier.

Magnet is great for bolt retrieval .
« Last Edit: December 19, 2013, 01:57:23 PM by rb550four »
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
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http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline Maurice

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Re: CB550 top end rebuild
« Reply #55 on: December 19, 2013, 02:22:07 PM »
Thanks. Ah well, and here I thought I was clever for once ;)

What about that camshaft? Ok to run or should I start lining eBay's pockets?

Offline rb550four

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Re: CB550 top end rebuild
« Reply #56 on: December 19, 2013, 02:36:46 PM »
The camshaft doesn't look worn ,still smooth, no damage to the tappets-nice and smooth.... just an air bubble in the cast on one lobe... unless it has obvious hairline or stress cracks, I'd run it.

Wasn't dissing the magnet, tried it before, just offering another option. The world is always looking for people that think out of the box, even if you weren't the first to come up with the idea, doesn't mean it wasn't a good idea.
« Last Edit: December 19, 2013, 02:46:22 PM by rb550four »
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline Maurice

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Re: CB550 top end rebuild
« Reply #57 on: December 21, 2013, 12:56:35 PM »
All buttoned up. Nothing broken or lost. Adjusted cam chain tensioner + valves, installed exhaust and carbs.

Started up 4th or 5th kick. But it did start and idled a bit. Wasn't running great though.

Saw some oil on the engine, not sure if it was leaking or it's the "assembly oil" running down. Heart sank a bit but thought to myself "patience".

Battery was reading 11.6, pretty sure that's why it ran like crap, put it to charge and wiped the oil.

Came back from lunch, battery was reading 12.1 or so, pulled choke, started first kick from stone cold.

Let it run, gradually pushing the choke until it held a good idle. Started smoking from the cylinder fins, smells like the stuff I hosed them down with to try and clean them, looks like it's burning it off eventually it stopped. Checked all the gaskets and no oil. Let it run to temp, took a little video I'll be posting later to show how it runs once warm.

Too early to tell, but at least it does not appear to smoke out the exhaust anymore, only water vapor, and apparently no leaks on the engine that I could see. Pretty happy at this point.

Now need to finish the rest so I can ride it: complete electrical, seat, ...

Offline dave500

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Re: CB550 top end rebuild
« Reply #58 on: December 21, 2013, 01:17:23 PM »
youve done well!,dont let it idle too much,the magnet on the nut is good,i slip the same type magnet into a deep socket,it holds the nut and you can hand spin it up,same for removal you dont get the nut wedged sideways in some of those nooks and crannys.
« Last Edit: December 21, 2013, 01:19:01 PM by dave500 »

Offline Maurice

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Re: CB550 top end rebuild
« Reply #59 on: December 21, 2013, 03:56:15 PM »
Because it's air cooled right? Yeah as soon as it was warm I shut it off. Today was 50 outside too, one reason I wanted to finish this up quick before it's cold again.

Thanks guys for the advice and good words. Much appreciated, I learned a lot.

Offline Maurice

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Re: CB550 top end rebuild
« Reply #60 on: December 21, 2013, 04:07:36 PM »
The engine in this thread running at:

Wiring needs some improvements, but ignition + charging actually works well, believe it or not :D

Offline DustyRags

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Re: CB550 top end rebuild
« Reply #61 on: December 21, 2013, 05:23:14 PM »
AWESOME! Sounds good! Synced the carbs yet?
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 #62 on: December 21, 2013, 06:48:41 PM »
Thanks! Bench synced only for now. Will vacuum sync when I can ride it.

Offline rb550four

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Re: CB550 top end rebuild
« Reply #63 on: December 21, 2013, 07:22:28 PM »
Congrats on the start up.
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline Maurice

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Re: CB550 top end rebuild
« Reply #64 on: December 23, 2013, 06:05:12 AM »
Would not have been possible without the wealth of knowledge and good folks on this site.

Last pics I took. After that it was a blur of putting screws back on.

The rubber band technique, with new tappet screws backed out all the way.



I think this makes it less likely to bend a valve stem.



New gasket and silicone lube to help hold it in place.



Love this lube, dissolves in oil and is chemically neutral. Also seems to revive old rubbers a bit. Yes it's a lovely bedsheet and no, it's sitting on my bench.



This perspective makes my fingers look fat. While tightening the cover I would wiggle the tappets to make sure nothing was binding. There's always one that will start binding, I just rotated the crank a bit to help settle everything.



That's it for pics. After that was valve adjustment once all bolts were tight on the head. This took a while because the gauges are hard to slide into the openings. I'll redo the adjustment soon, because running the motor was suspiciously silent in the drivetrain department. Maybe it's adjusted right but I want to make sure they're not too tight.

During this whole ordeal I noticed that torque settings were really low, the head cover bolts/screws don't take much at all.

At any rate, thanks again everyone.

Offline DustyRags

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Re: CB550 top end rebuild
« Reply #65 on: December 23, 2013, 10:09:57 AM »
Excellent job! Another one breathing and pounding!
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 #66 on: January 03, 2014, 12:38:39 PM »
Just a quick update, not related to the rebuild but just to mention that I've tested the following battery: http://www.amazon.com/gp/product/B009II5DAW/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

And it seems enough with kickstart only. Gets 14v above 2k RPM but I imagine it'd deplete rather quick just idling. Since you're not supposed to let it idle too long should be a non-issue.

It's a very small and light battery, despite being lead/acid AGM. Stock charging system should accommodate it. While I'd like to test Li-ion batteries I just don't think they're very safe with a "dumb" charging system.

Will report later, can't really do much it's so cold (battery does perform in this cold, interestingly) so we'll see.

Offline eastyork1977

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Re: CB550 top end rebuild
« Reply #67 on: April 18, 2014, 04:37:20 PM »
Great build and post.
Got a question.. How did you get those pistons so clean without taking them out of the jug?
'73 CB350G
'75 CB400F
'77 CB550K3 "Swayze"
'78 CB550K Stock
'78 CB750F2 Stock-ish

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Offline Maurice

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Re: CB550 top end rebuild
« Reply #68 on: April 18, 2014, 06:21:15 PM »
Hey thanks. Should be able to register it and ride soon. Can't wait.

The pistons were easy to clean, just some acetone and carb cleaner and a rag. I guess the engine was not pushed too hard?

Offline Maurice

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Re: CB550 top end rebuild
« Reply #69 on: May 12, 2014, 06:20:31 AM »
An update since the engine rebuild. Took a while due to crappy weather and some setbacks (forks + lower tree bent, long time waiting for jets to show up, ...), but I deem the bike safe and reliable enough to use it:



It's a... "work in progress" cosmetically, but I want to ride it the weather is finally getting so nice. And it does ride wonderfully. Not a big fan of the pods although I think they are tuned ok. The bike pulls ok all the way through but there is some spitting through the carbs at the crack of the throttle when rolling. A tad on the lean side still, just shy of cutting out WOT. What I do to compensate that is saturate the filters with goopy dirt bike filter oil. Seems to work well. Disclaimer: the pods go as soon as my airbox setup is complete.

Regarding the rebuild, so far has not leaked a drop of oil, and exhaust does not smoke anymore. I did not use any sealant anywhere, wanted to try that first, we'll see how it holds. Clutch was sticky as hell at first but after a few starts is now smooth. Finding neutral at red lights is easy although there is a nice false one between 4 and 5th.

Some observations (FTR I own and have ridden plenty modern bikes):
- the front brake sucks. No other way to put it. It works but requires anticipation. The rear brake works decent. I have a second caliper/disc waiting.
- 750 shocks make the bike handle real nice. It's a rail and corners with confidence, yet not too stiff when the road gets rough which is frequent after this winter.
- it's a lot of fun to ride!

Cheers

Offline calj737

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Re: CB550 top end rebuild
« Reply #70 on: May 12, 2014, 07:15:15 AM »
The front brakes don't suck, they're 40 year old technology. Properly serviced and operating, the work well. They are NOT dual piston units on floating, ventilated light weight rotors. Yes, you do need to think more about your technique when operating a 40 year old bike, but with some experience on this machine, you'll find that you can ride it well within the limits of a new riders on modern bikes. Technology does not replace experience.

If you're adding a second brake up front, seriously consider thinning and drilling both rotors to lighten the mass weight. AND, install a fork brace. The factory tubes were not meant for the system you're considering. Given you're fender-less too, there's added stress on those tubes. You'd be surprised how much better your bike will handle with those additions.

If you revert to an airbox, what happens to your electronics tray?
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Maurice

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Re: CB550 top end rebuild
« Reply #71 on: May 12, 2014, 07:29:16 AM »
Ok, I'll qualify with "by today's standards" for the brakes. I still think they suck ;) But you are right, knowing that it's the way they work you can use them as intended.

Thanks for the tips on lightening the rotors, I'm also currently cleaning the fender that's why it's not on there BTW. Handling is predictable enough though, and I am lucky to have some nice quiet back roads for my commute which don't allow me to go too fast.

I will be using a pod stuck to the plenum. To me the airbox is the plenum, not the piece holding the filter sorry for the confusion. This should leave enough space for the battery/wires. IMO the plenum is what is critical for proper tuning, the actual filter piece less so.

I think I prefer side covers for the triangle but I got this frame hacked... I will probably just add some tabs/flat plates there.

Thanks for looking

Offline calj737

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Re: CB550 top end rebuild
« Reply #72 on: May 12, 2014, 07:36:51 AM »
Yes the handling is predictable now. Duals will change that. Be aware of that is the caveat. A fork brace is inexpensive but invaluable for duals on stock forks. Member Godferrey offers great thinning and drilling services.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Maurice

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Re: CB550 top end rebuild
« Reply #73 on: May 12, 2014, 07:38:31 AM »
Oh ok got it. Thanks!

Offline Maurice

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Re: CB550 top end rebuild
« Reply #74 on: June 25, 2014, 08:57:58 AM »
Some follow-up as I had more time to ride the bike. Engine still not leaking, put about 600 miles on it since rebuild, commuting and tuning (read: WOT operation involved).

I had some trouble tuning because of my setup. Will post pictures of my airbox gizmo soon, but basically just some ABS piping coupled with a 3"x5" giant UNI pod. That and the 4-into-1 pipes.

But as of today it is very street-able. Starts first kick, idles like a swiss watch just above 1k, runs real smooth and pulls hard in any gear from 3k to as high as I dare rev it.

Will post pics and details on carb settings for reference in case somebody is in the same boat.

BTW, is there a thread anywhere listing people's setups and carb settings? If not I think it'd be useful, there is one such on the Hawk GT forum and it's quite instructive.