Topic: 1977cb550 leaky valve cover and stripped bolts

[kakon864]

Hello all, haven’t said much here in a while, but been having some trouble with my 77’ cb550. Been going smooth and putting some miles on it, still pretty low at only under 21k and I rebuilt it around 19990. Ever since the last time I took the valve cover off and put it back on there has been a leak on the right side next to the little side covers with the two o rings. I thought it was leaking there and tried to put some sealant behind the orings which didn’t help and then put some yellow Teflon tape as I saw in other posts to help, but still leaking a pretty decent bit( my entire leg and side covers will be dripping with pill after an hour ride lol) I was tighten down the bolt that holds down the bracket for the side cover to see if maybe that was causing the leak, but it stripped out… I’m not sure what to do from here, is there any way to fix the stopped hole in the head?

[Flyin900]

Your going to have to pull that cover and either use a Heli coil or Time Sert to fix the stripped hole. Replace all the gaskets and O rings that are part of the sealing system for the cover while your in there.  Those gaskets are 50 years old and need to start collected old age security and retire.

Apparently there is a procedure required to reinstall that top cover correctly without damaging the rockers. Someone will come along to outline that procedure.

[goodtryer]

There are 2 crushable washers that go on that bolt, one below the bracket and one above. I had the same issue on my 77 after replacing the o-rings; went away when I replaced the washers

And, yes, you're in for a thread repair. Don't cheap out on the insert. Get a good one and follow the directions fully. It's not rocket science but you only want to do it once.

Good luck!

[flatlander]

yes, it must be those crush washers. new copper ones will do the trick.

if you replace the gasket and o-rings, don't forget the rubber pucks under the cover. they are bot usually part of the aftermarket kits but honda OEM ones are available.

[goodtryer]

Apparently there is a procedure required to reinstall that top cover correctly without damaging the rockers. Someone will come along to outline that procedure.

The technique is referred to as the "rubber band trick". Use the forum search function and you'll find a bunch of references and descriptions of it (include the quotation marks so the search is for the complete phrase).

In short, you use rubber bands over the top of the valve cover, the end loops of the rubber bands go down through the tappet-cover holes and then wrap around the valve lifters. This holds them up, away from the valve stems to keep them from binding as the cover is being maneuvered into position.

It is also important to fully back-out the valve adjuster (the nut-screw combo) so that there is the maximum possible clearance between the lifter and the stem.

[TwoTired]

If the tappet adjuster aligns as shown below, the valve stem bends as you tighten down the cover.  So, don't do this.

Back out the adjusters as far as possible.  If you don't want to fiddle with each rocker during install, then string or rubber bands will hold them up, minimizing the risk of valve stem bending.  Still need to be wary, though.

Cheers,

[bryanj]

Personaly i would remove the head to helicoil that hole as the oil to feed the cam comes up there and any swarf is a definate no no

[Little_Phil]

Just checked a head and it seems that the tapped hole does not break out into the oil gallery in the head. BUT by the time you open it out for an insert it may well do and swarf there will damage bearing surfaces. Awkward to do as it is in a dished casting. Not room for a timesert. Crush washer is below bracket only. It was aly I think, don't think copper will do but there are alternatives. (dowty washer?)

[goodtryer]

Crush washer is below bracket only. It was aly I think, don't think copper will do but there are alternatives. (dowty washer?)

Phil,

You are correct on the washers. From the manual: "Chromium-plated copper washer on top and aluminum washer on bottom." I just used what I had at hand which is a variety pack of copper crush washers I got on Amazon. After a few hundred miles with the new o-rings & washers, it's been leak so far. Time will tell.

BTW, I also bought a variety pack of those dowty washers but haven't used them on anything yet.

Cheers!

[Flyin900]

I am not familiar with the area specifically, yet if Bryan indicates it is a oil galley I would tend to believe him. The further support is the fact that that bolts has both a aluminum washer and a copper washer would indicate it requires some sealing. A normal valve cover bolt would only have a flat washer under the flange bolt head.

I appears that repair needs some further investigation before work is done. If there is no room for a Heli Coil or time Sert then look below at another possible option.

[Kevnz]

I'm pretty sure that hole does go into the oil gallery; why else the soft washer, and why the oil leaks from that area if not properly sealed? Mine also has a helicoil, probably from someone trying to fix an oil leak.

[flatlander]

this is not a mystery: there's oil under that bolt, anyone who ever looked under that cover knows that. it needs to be sealed. alu or copper washers will both work.

the remaining question is, how can the thread best be repaired? it's a tricky spot, small space and a dished surface. not sure a timesert can be done but helicoil should work, with some caution?

here, the hole on the far right is the bolt hole. just to the left is the oil galley feeding the cam journal:

[bryanj]

Look on the outside and you can see the plug blocking the machined oil gallery plus lay a head gasket on there and see where the oil feed is

[kakon864]

So I can’t just remove the valve cover and put a helicoil in? Would a copper washer be fine for the bottom? And what about the top washer, is that just a normal one?

[bryanj]

You can but you risk tapping debris blocking the oil gallery, your bike your choice

[flatlander]

remove the head, otherwise you risk getting metal particles into the oil galleys from the drilling which is asking for trouble.
look at the diagram that goodtryer posted: both washers need to be sealing. alu or copper - your choice.

sorry, all this has been pointed out before so i'm just repeating. is there anything more specific you need advice on?