Cracked/Welded Valve Cover

[Shaughn]

(on the new to me this summer 77 '750)

So....

I'm not sure how I missed this before, but as I cleaned the grime off of the valve cover to do an initial valve clearance check, I found a weld across a major portion of the valve cover over the #4 exhaust cam.



What the fduck could have caused that? My guess is some kind of major overtorquing of the bolts, but even that seems a stretch... Any ideas?

While it seems more plausible that that somehow happened while the cover was off of the bike, due to the positioning, there are cracks at the #4 intake, and #3 intake bolt locations as well(no welding there). Whoever did this welded both inside and out apparently, as there is excess material on the inside of the cover too, yet they also sealed the cracks with some kind of hard coating, and coated the aforementioned cracks as well. It looks like it is the indian head shellac like you'd use on a freeze plug. I have no evidence of it leaking, but I feel I need to do something about this now that I know about it. Any thoughts?



Oh, and I'm not rushing to put if back on just yet, 4 out of 8 shims were unmarked, and
like a fool I left both my digital caliper and my micrometer sitting on my desk at work...35miles away. >-(

[Hoges]

Looks like a pretty good(professional) repair to me, and whilst untidy should be okay for quite a few years yet. I've had aluminuim boats repaired in the past like this and have had no problems. BUT, it does tend to weaken the surrounding area and can be an ongoing prob. So, I would keep an eye out for a replacement just in case for a spare. Must have happened over tightening maybe, strange one that.

[psyguy]

get a "new" one from ebay and the like
keep that one as a spare
or if you're not bothered about the apearance, just use that one, looks all right

[Shaughn]

Ultimately, what concerns me more is not the results (appearance) but the cause. I just can't fathom what would have created a crack in that location like that.
The jugs look good, so I wonder if this didn't happen off of this machine.
There are 'new'ish looking gaskets from the crankcase up visible from the outside, and the PO's story was that he rode it for a year (2007) after buying it from "a guy who thought he was a motorcycle restorer, and had a barn full or project bikes, and was selling this one to fund other projects".
The PO was selling because @ 135lbs, he was too small for the bike. All sorta plausible, except that when I ran into someone else the PO's age from the same small town, and asked casually what they thought of him the answer was "he's a weasel" without skipping a beat. argh. I think the bulk of this is that he may have known about the charging problem, but lied about it, but there have been half a dozen other things I've found showing he didn't know what PM to do even if he wanted to....

[robertbarr]

I had a bolt frozen into my 850's cam cover, and the only way to remove it was to break it. In fact, for a second there, I thought that was my cam cover. Now, in my case, the '82 850 had a different bolt pattern than previous 850's and so was impossible to find a replacement for, so I had to work with the broken original.

I had it professionally welded back together, hand-planed the gasket surface, and put it back together. No big deal other than the cosmetic blurb, and no leaks.

Unless the cosmetic flaw bugs you enough (or unless it leaked oil before you pulled the cover), I wouldn't worry about it. It looks like quality work.

[Shaughn]

I had a bolt frozen into my 850's cam cover, and the only way to remove it was to break it.

Well, that sounds plausible.
Did you use anything to coat the seams like this one has on it?

(btw, Thank you for the excellent o-ring kit, went in a few weekends ago very nicely)

[Nicholaschase29]

There is no way that was cracked by over-torquing the bolts because they would strip in the aluminum cam caps/ cylinder head far before they would break the cover.. imo

[hp1000s]

I've got a chrome 750/850 valve-cover that has no use to me...if you're interested.
Hugh

[Clayton!]

The black crap is PROBABLY JB Weld. It's a metal bonding epoxy, strong as an ox IMO. If it's coated, I'd check it periodically for leaks, but if your concerned about it breaking again, I honestly have not had a single instance of it breaking. I actually used it not too long ago on a 850 triples to repair the housing of the Tach cable to the block, let it harden up over night, good to go.

[Shaughn]

The black crap is PROBABLY JB Weld. It's a metal bonding epoxy, strong as an ox IMO. If it's coated, I'd check it periodically for leaks, but if your concerned about it breaking again, I honestly have not had a single instance of it breaking. I actually used it not too long ago on a 850 triples to repair the housing of the Tach cable to the block, let it harden up over night, good to go.

Hi Clayton,

It's not JB Weld, I know that product well. What's on there is more of an translucent amber, thin and hard, like a lacquer. I'm 90% sure its indian head shellac, but that kind of shellac is meant as a gap filler, not a over the surface seal, which is why I'm considering using something else. I've used JB in the past, and in direct contact with oil had mixed results.

Good to see another triple to GS convert, my last ride was a 78 XS750.
I wish I hadn't sold it. (Not sure why I keep buying '78s, though )