Topic: '76 CB550-inside look at tappet noise

[denward17]

Hey Guys, Trying to isolate a noisy CB550 top end.
Going through some steps and took the valve adjuster covers off to check valve clearance.

Top of all valve springs/retainers are wet with oil, so assume oil is getting to top end as it should.

Looking inside the adjuster covers on 2 exhaust and 1 intake I see what looks like witness marks where the rocker arm adjuster nut might be hitting inside the cover.

What do you guys think?  Have you seen this before?

Assume the valve cover rocker shafts are worn?  Or could the valve clearance be out enough to hit?

[MauiK3]

That does not look right, what could be causing that?

[calj737]

Best to remove the valve cover entirely now and inspect the underside of the rocker arms. You can also more closely inspect the rocker shafts for wear.

[willbird]

That does not look right, what could be causing that?

I wondered if a PO had a nut come loose and move around in there ?

[Tracksnblades1]

That does not look right, what could be causing that?

I wondered if a PO had a nut come loose and move around in there ?

If not, he should see a witness mark also on the culprit that offended his cover..

[denward17]

Just checked clearances, ad am surprised by what I see.  I initially set all to spec (I=.002" E=.003")

Settings now:

      1             2             3            4
I  >.008       .005       .004        .005

E    .003       .003       .004        .004

Exhaust clearances are consistent, but Intakes grew quite a bit, especially #1 (greater than .008, didn't have anything to measure that would fit).

I haven't checked the nuts yet to see if all are tight, but they are all on at least.

On the exhaust #1 and 2, I can wiggle the rocker arm side to side quite a bit.

How could the intake clearances back off that much just with 30 miles on it?

[willbird]

Just checked clearances, ad am surprised by what I see.  I initially set all to spec (I=.002" E=.003")

Settings now:

      1             2             3            4
I  >.008       .005       .004        .005

E    .003       .003       .004        .004

Exhaust clearances are consistent, but Intakes grew quite a bit, especially #1 (greater than .008, didn't have anything to measure that would fit).

I haven't checked the nuts yet to see if all are tight, but they are all on at least.

On the exhaust #1 and 2, I can wiggle the rocker arm side to side quite a bit.

How could the intake clearances back off that much just with 30 miles on it?

I know you know but still need to ask, is/was the engine stone cold, as in has not run in 12 hours cold ??

Bill

[denward17]

^Yes cold, ran it yesterday for about 3 minutes.

All adjuster nuts were tight.

[denward17]

Pretty sure I found the problem.

Took off the end caps and the outside rocker shaft (#1-2 Intake) will visibly rock up and down.

Looks like I need to locate another valve cover with the pinned shafts ('77 and '78 models only I assume).

Will the K and F models work the same?

[bryanj]

Rocker shafts have worn the cam cover holes oval, you need another cover preferably 77/78 where the shafts were pinned

[flatlander]

Will the K and F models work the same?

yes they're the same.

[calj737]

Pretty sure I found the problem.

Took off the end caps and the outside rocker shaft (#1-2 Intake) will visibly rock up and down.

Looks like I need to locate another valve cover with the pinned shafts ('77 and '78 models only I assume).

Will the K and F models work the same?

The option is to have a machine shop replace those bushings with new ones. Would be a bit of a custom job, but really shouldn’t be that expensive. They can easily check the shaft for concentricity and bore the old bushings out and press and ream new ones in. They just need a boring head small enough to do the work.

[bryanj]

There are nobushings, the shafts fit direct into cover, could be bored out and bushes fitted but probably cost a lot more than a used cover

[denward17]

Would these work?

https://www.ebay.com/itm/126188934467?chn=ps&norover=1&mkevt=1&mkrid=711-166974-028196-7&mkcid=2&mkscid=101&itemid=126188934467&targetid=2285861344478&device=c&mktype=pla&googleloc=9009722&poi=&campaignid=20773344909&mkgroupid=163822270247&rlsatarget=pla-2285861344478&abcId=9338585&merchantid=408535715&geoid=9009722&gad_source=1&gclid=Cj0KCQjw6PGxBhCVARIsAIumnWbhN0pw6L0Bfeur_-voB41HFh5GJ9iuXAKeeoCsMLYMshQmg2UKalwaAo_wEALw_wcB

https://www.ebay.com/itm/126188934473?itmmeta=01HXFFWA9ZGPMAJC1V4S1JQKMW&hash=item1d61725549:g:D4AAAOSwWs9lVYG7

Even though they are indicating for a 1975 CB550, but I see the holes for the pinned shafts.  Is that I all need to look for?

[denward17]

I purchased this one, hope it works.

https://www.ebay.com/itm/404748483644

[calj737]

You need to make sure and reuse your rockers with your cam and valve tops. There’s a wear pattern that you want to observe.

[denward17]

You need to make sure and reuse your rockers with your cam and valve tops. There’s a wear pattern that you want to observe.

Understood....

How do the pins come out of the "pinned" rocker shafts, from the top down?

[grcamna2]

Following

[craz1]

You will need the shafts and pins. Doesn't look like you get the shafts or pins with those covers. When I rebuilt my CB550 I located new shafts form Europe, which are hard to find new. I also sent my cam and rockers to common motor and had them reworked. Cost a bit but well worth it in my opinion. Smoothest running bike I have owned. (Which has been sold)

I do have some used shafts and pins which are on ebay at the moment. Shafts have some wear but usable. If you need them let me know.

That wear is common for the early CB550 so you best bet is the 77-78 cover.

[grcamna2]

I purchased this one, hope it works.

https://www.ebay.com/itm/404748483644

I purchased an exhaust system from them;good folks from the Ukraine.
I rode over and picked it up from where I live and it saved me on shipping.

What's the visual difference(the type of hold-down pins for the rocker shafts)between rocker shafts hold-down pins on the one you just purchased(1975)here,or the 1977/78 rocker shafts pins ??

There are threads here on the forum with much more information on solving this issue,even on an older model cam cover.

[bryanj]

From the pics they posted you will not need to change the rocker arms, especially as your have been running on wandering shafts and will be worn "wrongly"
Post some close up pictures of the pads on the cam followers when it arrives and i will comment better them as they are hard plated.
They one you bought was a far better deal as it came with all the internals and the expensive tacho drive casting.

READ THE MANUAL CAREFULLY about refitting the cover or you will bend valves and break guides

[flatlander]

You will need the shafts and pins. Doesn't look like you get the shafts or pins with those covers.

yes they're in there. pins are under the 4 nuts you see on the photos in the middle of the cover and without shafts, the rockers would stay as neatly in place.

[flatlander]

How do the pins come out of the "pinned" rocker shafts, from the top down?

yes, tap them out. careful not to damage the threads (keep nut on).

[RAFster122s]

Dang that is a high price for the late cover, but you are pulling trigger quickly rather than waiting for a deal...
But, cannot blame you for that. It is years after I picked up my cover, so that is to be considered...
Everything is so stinking high these days and low fixed incomes suck

[bryanj]

Those pins rarely "tap" out, they frequently get badly damaged removing them, like i said i would fit the cover complete as the Hondas are not like old cars