Author Topic: 550k Cylinder Head Cover  (Read 958 times)

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Offline redrider736

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550k Cylinder Head Cover
« on: May 19, 2016, 12:02:20 AM »
I have removed my Cylinder Head Cover off my 1978 CB 550k for a 650 Cam swap.... What OEM replacement parts should I order for the for the Cylinder Head Cover install other than the Cylinder & Breather Gaskets ??
« Last Edit: May 19, 2016, 12:05:36 AM by redrider736 »
78' CB550k (Not Run'n / Basket Case Project)
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Offline DaveBarbier

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Re: 550k Cylinder Head Cover
« Reply #1 on: May 19, 2016, 07:00:50 AM »
If it were me, and because it's such an easy job to do in frame I'd replace only the main cover gasket and put the rest back and tend to it if I see anything leaking. Unless anything needs obvious replacement.

If you wanted to replace all o-rings and rubber bits there's a lot there like tach seal, end cap o-rings, tappet cover o-rings...not to mention all the little crush washers for the screws.

Just be sure to use rubber bands to hold the tappets back when you install so you don't bend a valve. 



Offline redrider736

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Re: 550k Cylinder Head Cover
« Reply #4 on: May 19, 2016, 03:06:22 PM »
I think I remember reading something on here about the Pucks as mentioned above and "copper washers" ??

Just planning to put a small order in and want to get everything all in 1 shot..

Once again you guys are the best !!

78' CB550k (Not Run'n / Basket Case Project)
77/78 cool 2 member #269

Offline alacrity

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Re: 550k Cylinder Head Cover
« Reply #5 on: May 21, 2016, 11:14:22 AM »
I think I remember reading something on here about the Pucks as mentioned above and "copper washers" ??

Just planning to put a small order in and want to get everything all in 1 shot..

Once again you guys are the best !!
There are two special washers that are hard to find/impossible to find- honda originally spec'd very thin aluminum crush washers to go under the long m6 bolts at either end of the cyl head cover.  You can replace these with m6 copper washers but they HAVE to be very thin ones. If too thick, they are therefore too sturdy, would require more torque to get them to squish and seal oil, and you run the very real risk of either having them leak because they didn't deform to seal/fill the gap OR you were on the verge of having applied enough torque for that to happen, but you just stripped the threads in the super soft aluminum in the head itself.   And if you then try to drill/tap to place a helicoil or time-sert, where do you think those metal shavings are gonna go?  Yep, down into your internal cyl head liking galley that feeds the camshaft.  Ng
I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.

Offline alacrity

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Re: 550k Cylinder Head Cover
« Reply #6 on: May 21, 2016, 11:47:53 AM »
I have removed my Cylinder Head Cover off my 1978 CB 550k for a 650 Cam swap.... What OEM replacement parts should I order for the for the Cylinder Head Cover install other than the Cylinder & Breather Gaskets ??
adding on here bro - I have done my fair share of these now and after getting f'd trying to cut corners I do this now and have no hassles or leaks.  A little more $ on the front side, zero worry or leaks on the other.

CLEAN CLEAN CLEAN.   Make the track I which the edge sealing ro-ring travels CLEAN and beautiful.  You want the new one to nestle in there and find uniform squish with out grabbing or binding on a burr or dried adhesive or whatever.  Be obsessive about this - but don't use wrong /steel tools/brushes and remove metal!

Order:
New curvy pre-shaped OEM sealing " o-rings" for cyl head cover track and breather track. 

Six new Honda OEM sealing washers (aka "pucks") I use HYLOMAR under these to ensure the seal. Be SUPERcareful to not use too much. You don't want the goo to squish up and out past the seal Ito oil galley next to camshaft. It's fine if some drips  down onto the head stud /nut below.

Ten m6 copper washers (fiche shows six to be used under the more central hold down screws plus two under outer edge long m6 flange bolts.  (You are looking at the parts fiche, right?  Western honda in Phoenix has one online, as do others). Take the remaining two: place some 220 grit emery cloth on perfectly flat surface, press copper washer with fingertip and make circles. Thin it down by 25% or so.  Use these where the discontinued "11mm" (odd external measurement honda applied here for some unknown reason) aluminum washers go.

And I also replace the stock JIS HEAD screws with stainless socket head cap screws (use anti-seize). You need low head ones or button heads for the 4 next to the valve adjuster caps.  Don't use 3:8" drive tools ever ever ever on these delicate parts.  Think of yourself as more of a jeweler than a mechanic... Or a Vet surgeon working in a puppy.   Small 1/4" drive tools with t-handles or bit drivers are great to protect you from yourself. 
All this comes gel the various ways I have screwed (literally) this stuff up before and had to do again, or made way more extra work for myself, or had it done and then it leaked... (Like from crappy cheap imitation pucks. -- THAT was a "genius" move that saved me five dollars or so - and resulted in having to pull it all apart again after 30@ miles 
I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.