Topic: Cam rocker Cover installation problems

[frostyCB]

Hey All,
I'm in desperate need of help!!! I'm pretty new to working on motorcycles, and need help diagnosing an issue.

I managed to get a sweet deal from a hoarder for a 1975 Cb550 (with 24,000 miles for $180) as well as a CB650 cam. After reading countless of threads on swapping the 650 cam I decided to give it a try. After installing the cam, which I found to be the easiest part, I began re installing the rocker cam cover. After feeling accomplished and buttoning up the engine back together, I tried rotating the engine a full cycle to make sure that everything was in proper order. Unfortunately it was not! It gets locked up at some point during the rotation of the crank. And wont go any further, therefore I'm deferring to the experts! 

I installed the cam using the marker at its end to be horizontal to the mating surface. This was done as instructed per manual. I also rotated the cam a full cycle without the cam rocker cover on to assure that it didn't hit the casing. After feeling like a loser, I removed the 650 cam and re installed the 550 cam, just because I'd rather get back to riding than find myself stuck bikeless. And re installation of the 550 cam it still was a no go.

Another detail: I have found on the number 1 cylinder side the right rocker shaft seems to not be perfectly aligned. I thought that this may be the issue. The rocker shaft might be bent/worn therefore not allowing the rotation of a full cycle. Is this correct? The link below has a picture in thread of what I'm describing.

 (http://forums.sohc4.net/index.php?topic=20408.msg212239#msg212239)

Can anyone help me diagnose this problem. I desperately want to get back on road. I'm hoping that this may be the problem and only requires a new type rocker cam cover. Any help would be appreciated!!!
-FrostyCB

[mitch500]

Did you lift the tappets up via removing the tappet covers and attaching a elastic band to the tappets? If you don't lift the tappets up you risk not seating the tappets with the top of the valve.. This will cause a binding and cause you big issues if you bend them.

There are various threads on this if you search... Or download the service manual.

Im giving a short explanation only because I can right a novel on a iPhone:)

[frostyCB]

I fear you may be right, I just went scouring the forum and found similar situations to mine. When I was re installing the cover, I lifted all the tappets by hand, and tightened them down when I thought that everything would be fine. I didn't read about the rubber band trick until recently. Ugh I'm hoping this fix wont be too costly, I'm hoping to luck out with ebay of if someone on here would be willing to donate a decent head that would be awesome too. 

I guess this might be my opportunity to also learn how to do a mild port job as well.  I'm just ashamed and a bit bummed that this is what is taking me off the road. I guess I'll just learn from my mistakes.

[Fritz]

Chances are that you bent a valve stem or two by not keeping the rocker clear off the valves while installing the cover.
That would result in not being able to turn the crank without force. The bent valves will stick in the valve guides. If you did not turn it a full circle yet, you might get away with trying to bend the valve stems back after removing the valve springs. A 10mm ring wrench used as a lever will do the trick, although your valve guides will suffer a it. Throw away the bent valves and buy new ones then.
Take off the cover and look if all valve stem ends are in a perfect line.
If a bend valve is not your problem, you did not align the camshaft correctly to the crankshaft.
Cranshaft must be at T-Mark 1-4 while the notch in the camshaft must face perfectly horizontal, in parallel with the cylinder head's sealing face.  It does not matter if it points to the front or the rear - camshaft is turning one circle while the crankshaft is doing two.
Back to the possibility of bent valves: Chances are high - if valves are bent - that the related valve guides are broken too. They do not take much lateral force. In this case, your best option will be a good used head (about $100).
You rocker cover worn is not such a big issue. It will not stop your engine running, but will need taken care of eventually. So if you are going to buy a head, try to get a good cover too.

[TwoTired]

From the Honda CB550 Shop manual.

Misalignment causes bent valves.  Cover removal is easy.  Installation takes care.

[frostyCB]

Thanks you guys!! You guys are truly a wealth of information! I'm hoping to find a decent used head over eBay since the motorcycle junkyard in town is quite expensive.

@Fritz: I'll definitely look through the head and valves as you instructed. It really couldn't hurt, plus I'm interested in learning more about the bike and all its tid bits!

@TwoTired: Thanks for the picture, they are definitely worth a thousand words!

I do have a couple of more questions:

1) What should I be looking for when purchasing a used head?   Are their any signs of obvious wear that I should look out for?

2) Would it be okay if I kept the same cam rocker cover?

3) And does it matter if I use a CB500 head? (I believe they should be interchangeable, but I'd like for someone to confirm this. Or should stick to just finding a CB550 head?)

[Greggo]

CB500 heads will work.  A question: did you rotate the cam inside the head, and the rocker cover to make sure the larger lobes still cleared?  Some folks have had to scrape some material from inside the cavity to allow full rotation of the cam...I fortunately didn't have to remove material, but it's easy if you do. 

If your rocker cover has the issue shown in the first pic of this thread, you'll want a new one.  It causes the rockers to hit the cam lobe at an uneven angle, causing damage.

Not sure about head shopping advice, other than stay away from badly bent fins.

[frostyCB]

@Greggo: Thanks a lot for your response. Yes I did rotate the cam completely. I remember reading a post about someone having to shave bits of the inside of the case to allow the cam lobes to clear. I was fortunate enough to avoid doing this... well until I had to deal with my present situation with bent valves and broken guides. :/

[bryanj]

You say you lined up the cam notch but did you have the crank on the correct mark?

[TwoTired]

If the cylinder cover/cam cover has elongated shaft holes, they usually wear unevenly which kants the cam follower on the cam lobe.  This can cause uneven wear, both the the cam lobes and the follower faces.  It should be evident on the old cam, as one side of the lobe will have wear the other side doesn't.  It's okay for a while to use it this way reusing old parts, but if you are installing a cam with nice flat lobes, I wouldn't use a worn cylinder cover for the new parts.  Look for a 77-78 CB550 cylinder cover, as the shafts are fewer and pinned so the cover wear can't occur.  Also check the cam follower faces you intend to mate with that 650 cam.  If there is galling or wear through of the surface plating, replace with new (or newer) if you want the 650 cam to have longevity.

[dave500]

i back the tappet screws out all the way,you still have to make sure and guide the rocker over,you have slightly less spring pressure to deal with then,also dont winch down on those forward cover screws much untill the cover is squared down,youll snap the little ear the screw goes through off.

[hymodyne]

I've got a couple  500/550 rocker covers. PM me if you have parts you need.

Hymodyne

[1974cb550k]

Are you 100% positive the cam lobes clear the head? Rotate the engine at least 360.

[frostyCB]

@1974Cb550k: I'm pretty sure I was able to rotate the engine completely with the 650 cam in. So I know for sure that the lobe heights were not the problem. I intend on taking off the head this weekend. So updates will be given! I'm hoping to get a new used head but finding one in decent quality with all the parts is kind of hard.

@Hymodyne: I might take you up on that offer. I'm actually in need of a 77-78 CB550 cylinder cover. I figure that if I'm going this deep into the engine, I might as well do it right. I'll definitely send you a PM and we can discuss it further.

@Twotired: Longevity is absolutely what I'm after and intend on doing this rebuild right. I'll keep my eye out on EBay and the sales portion of this forum to find the specified rocker covers.

@dave500: I believe that's where I went wrong, I began tightening the screws right after installing the cam. Not really cautioning the valves as much as I should have. Thinking about it now, it makes so much sense to back out all the tappet screws out. Goodness I should have made a post BEFORE actually carrying out the install. I might have been better off.

@bryanj: Yes sir, the marks and cam were installed correctly. I just screwed up the rocker cover.

General question: Should I be worried if there is rust in the combustion chamber? Can it be removed? for example the link below

http://www.ebay.com/itm/1977-honda-cb550-cb-550-four-hm347-head-/290615979891?_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D5%26po%3DLVI%26ps%3D63%26clkid%3D7312621047768259541#ht_2092wt_754

[dave500]

that looks bad,avoid that one,,itll have pitted valves and valve seats and need money spent if it can be resurected,,you might even find a good complete engine,use its head and have a spare barrel and transmission?

[MRieck]

If the cylinder cover/cam cover has elongated shaft holes, they usually wear unevenly which kants the cam follower on the cam lobe.  This can cause uneven wear, both the the cam lobes and the follower faces.  It should be evident on the old cam, as one side of the lobe will have wear the other side doesn't.  It's okay for a while to use it this way reusing old parts, but if you are installing a cam with nice flat lobes, I wouldn't use a worn cylinder cover for the new parts. Look for a 77-78 CB550 cylinder cover, as the shafts are fewer and pinned so the cover wear can't occur.  Also check the cam follower faces you intend to mate with that 650 cam.  If there is galling or wear through of the surface plating, replace with new (or newer) if you want the 650 cam to have longevity.

They are getting more and more difficult to find(at a reasonable cost).

[Lostboy Steve]

I #$%*ed up my stock 77 rocker cover like an idiot and then had to buy an older one because its all i could find in good condition. Long story short everything works fine the one I found was nice and tight. I will say this, on the exhaust side the tappet covers don't fit with my nice stainless allen bolts installed.