Valve Stem Seal process

If it's broken or just needs tweaked

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frankinstyn
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Valve Stem Seal process

Postby frankinstyn » Mon Oct 09, 2006 11:34 pm

Hello all. I've decided...after much information from you guys of coarse...to replace the valve stem seals myself. I've done them before but only on grown-up sized engines and larger.

So I'm going to remove the head and do it that way instead of trying the tricky way of keeping the head on. So the tools and such needed.


Valve spring compresser ( I have a couple different sizes but will buy another if neither of these work)
wrachet set and end wrench set for removeal of head (already have)
suran wrap to completely cover and protect engine while head is removed
feeler guages for valve clearance adjustment (.002 and .003)

1 - Head gasket (includes oil seals on either end right?)
1 - rocker arm housing gasket/seal
1 - valve cover seal
8 - valve stem seals
8 - valve spring keepers


new spark plugs
acitone for cleaning of gaskets and parts
gasket sealent

Anything else I'll need?

Also, I would like to know of any sources for these parts. I would rather not buy a complete gasket set. I am also a college student so funds are of coarse limited.

Thanks to all.


Image

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Thats the bike as when I purchased it. I've already bought a nice faring, tool bag, and hard leather saddlebags. Also replaced the hand-grips and foot rest with new. The more chrome, the better.

Frankie
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Chris
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Postby Chris » Mon Oct 09, 2006 11:44 pm

Hmm...plastic wrap... now there's something I never thought of. Good idea! Thanks.
1980 CB650c

frankinstyn
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Postby frankinstyn » Mon Oct 09, 2006 11:53 pm

No problem. Glad I could help. At my shop we wrap everything with it. It really seals everything out. Don't be stingy with it either. We simply wrap the whole engine with it.
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Volker_P
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Re: Valve Stem Seal process

Postby Volker_P » Tue Oct 10, 2006 12:52 am

frankinstyn wrote:
1 - Head gasket (includes oil seals on either end right?)
1 - rocker arm housing gasket/seal
1 - valve cover seal
8 - valve stem seals
8 - valve spring keepers


I think you will not need any new additional seals but the head gasket and the two 5x2.5mm O-rings at both ends. O-Rings are usually included in head gasket sets (see "Gasket set" thread for sources). Basically, even the head gasket can be reused when carefully removed and re-inserted with high-temperature grease but I do not know whether I should recommend that.
If you are very patient and careful and don't mind to do it possibly again, it may be worth a try.

Valve spring keepers are pairs, so you will need 16, but I think there is no need to replace them if you can remove them without doing damage to them or loose them when they snap away during removal or mounting.

Two basic points:
1. Clean up your engine, especially the heads of the cylinder head bolts (hidden between the spark plugs openings) with high pressure air or water before you remove any cover. It is time consuming to clean them later when everything is open. You may ruin the bolts heads or later the housing threads when mud/sand is falling down into the threads at the bottom of the cylinders.
2. Urgently use a small torque wrench for the 22 6mm cylinder head cover bolts and use the crisscross pattern in several steps (at least 4-5) for tightening. Also release should be done this way with at least 3 steps. A bent head cover wont get tight with a new seal and high torque while a flat, clean one will be perfect even at 8-9Nm with an old seal.

In case it was not already written somewhere, head removal works with the engine in the frame.


frankinstyn wrote: The more chrome, the better.

Your chain cover seems not be chromed but black plastic? You may get a chromed one, I would guess for the custom the plastic one is rather exceptional.

frankinstyn
Posts: 24
Joined: Sun Sep 24, 2006 12:09 pm

Postby frankinstyn » Tue Oct 10, 2006 1:08 am

Two spring per each valve? Interesting. Ok. So 16 keepers. I don't intend to break or damage any and havn't had problems before. I just don't want to have to wait and order later if I do manage to damage any.

As for warping the head, valve cover or anything else. I havn't had a problem there either. I do understand that these engines are a bit softer metal than what I am used to dealing with so I'll use extreme caution. I do have the book and always follow it closely for repairs on any engine.

The chain cover is black painted metal. Good point though. I had never noticed before. I didn't know there were chrome ones available.
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Volker_P
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Re: Valve Stem Seal process

Postby Volker_P » Tue Oct 10, 2006 1:34 am

frankinstyn wrote:I do understand that these engines are a bit softer metal than what I am used to dealing with.

In fact japanese motorcycles engines are made of butter with traces of some weak hardener. :lol:

frankinstyn wrote:Two spring per each valve? Interesting. Ok. So 16 keepers.

No, one spring per valve. I understood "valve spring keepers" being this two key parts that fit in the groove at the ending of a valve stem. But I do not know English technical expressions really good, so it was probably a misunderstanding.
Now I would be interested which part is called "valve spring keeper"?

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Ibsen
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Postby Ibsen » Tue Oct 10, 2006 1:59 am

I would also replace the seal pads that is covering the cylinder bolts. They are prone to leak as well.

And there are 2 coil springs on each valve, one inner and one outher spring. :)

http://cosky0.tripod.com/imagelib/siteb ... et=tlx_new

http://cosky0.tripod.com/imagelib/siteb ... et=tlx_new


http://cosky0.tripod.com/id6.html

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Volker_P
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Postby Volker_P » Tue Oct 10, 2006 2:22 am

Ibsen wrote:And there are 2 coil springs on each valve, one inner and one outher spring. :)

Oh, I am really getting old. I already see me asking some young passer-by to help me across the street to my motorcycle. :lol:

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DammitDan
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Postby DammitDan » Tue Oct 10, 2006 2:52 am

The valve spring retainer is the circular metal piece that holds the springs down. There is one per valve.

The valve spring keepers are the little metal pieces that fit inside the retainers to keep the valve stem attached to the retainer. There are 2 of these per valve.

So, per valve you have:

2 valve springs.
2 keepers.
2 base washers.
1 valve spring retainer.
1 valve stem seal
1 valve :D

frankinstyn
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Joined: Sun Sep 24, 2006 12:09 pm

Postby frankinstyn » Tue Oct 10, 2006 9:15 am

Ibsen wrote:I would also replace the seal pads that is covering the cylinder bolts. They are prone to leak as well.

And there are 2 coil springs on each valve, one inner and one outher spring. :)

http://cosky0.tripod.com/imagelib/siteb ... et=tlx_new

http://cosky0.tripod.com/imagelib/siteb ... et=tlx_new


http://cosky0.tripod.com/id6.html


Is that a factory manual online?!? That is so cool. I love the factory manual over any after market manual. Just so much easier to follow! Is there a place to download the thing completely? I'd really like an electronic copy.

Thanks for pointing that out. I forgot these things had seals there.
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Ibsen
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Postby Ibsen » Tue Oct 10, 2006 9:45 am

Yes, that is the Honda factory manual for the CB650Z, the model you didn't get in USA. The engine is the same though, but it does not cover the later CV carbs.
And it is the only online manual available.

frankinstyn
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Joined: Sun Sep 24, 2006 12:09 pm

Postby frankinstyn » Thu Oct 12, 2006 10:27 pm

So I purchased all the necessary seals and gaskets today. I searched forever for them at a decent price but ended up having to spend about $90 just for the stem seals, head gasket, and cover seals.

Soooo I said forget it and just ordered a complete gasket kit...which included valve stem seals. So now I'll have a few extra pieces but I did manage to save a few bucks.

https://www.partsnmore.com/motorcycle-gasket_sets.php?make=honda&category=gasket_set
Image

Also have all the tools, solvents and guidance necessary. I think I'll go ahead and tear this thing apart as soon as I recieve the seals and gaskets.

Thinking I should go ahead and keep a walkthrough with tons of pictures as I go. Anyone be interested in this?

Here are a couple of pictures of the bike as it sits today....as well as my other pride and joy. My beautiful 1980 volkswagen Rabbit!

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Oh yes, forgot to mention. I bought new tires for it. Just went to a shop for it and told 'em I wanted something that REALLY sticks to the road. These things are fantastic. I can really lean this thing over now. Feels so much better.

Image

Image

Image

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This last one is my favorite of my car. That 26 year old paint really shines!

Rode the bike all day today. Feels so great. Seems like it only really burns oil once the temperature gets up past highway cruising temps. Didn't smoke at all today as I didn't do any city driving. Anyway. Soon I won't have to worry about it! Man I love this bike!
Is the above comment is complete idiotic or ignorant please attribute it to the alchohol.

frankinstyn
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Postby frankinstyn » Thu Oct 12, 2006 11:53 pm

Oh yes and another question.

This is a dyno chart from a pretty much new 1980 cb650.

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and this is the dyno from my 26 year old 1980 cb650 with 10k miles and leaky valve stem seals.....

Image


whats going on here? disreguarding the difference in numbers...though 4hp is quite a difference considering my dyno was taken on a warmer day with higher the same humidity. Whats with the large difference in rpm?
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Volker_P
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Re: Valve Stem Seal process

Postby Volker_P » Fri Oct 13, 2006 1:17 am

Looks like in your r.p.m. axis there is a factor of two missing, maybe due to wrong setup or some fault of the dyno.
It cannot be correct. Torque seems wrong also as a consequence from that.

frankinstyn
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Postby frankinstyn » Fri Oct 13, 2006 1:23 am

do you think the hp and torque specs are still correct? It'd be nice to still be making stock hp after sitting for that long.
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