-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
“Like a Hole in the Head”
- Thread starter JRay77
- Start date
Maybe there was a defect in the casting. I’m interested in seeing what you discover.
Appears the piece just fell out. If you look in behind the spark plug, there is cooling fins. Shook out between these fins after???
Dang Johnny, that’s a head scratcher. Very interested to see what that head looks like when you get it off the motor. Be really surprised if you don’t have any cam damage.
0.35 in the video there are some marks on the piece .. One should be able to see a casting defect
at the break surface
It does not look so
I am at something hitting it but then it would be difficult explain it running without problems.
I would be careful rotate that engine A boroscope would be my choice especially since I have one .
there are holes look into ...
at the break surface
It does not look so
I am at something hitting it but then it would be difficult explain it running without problems.
I would be careful rotate that engine A boroscope would be my choice especially since I have one .
there are holes look into ...
I have read before that sometimes if something metal , like a valve keeper, is bouncing around up there, it can get wedged under the camshaft and break the head, just as you’ve described.
I'm betting something got between the cam lobe and the head. When you get it apart it will make more sense.
I think there was another thread about the same thing.
I think there was another thread about the same thing.
I think Jan and MM have the answer.
There is a thread, (cant find it), that had 2 or 3 valve adjuster thread marks on the inside of the head where the adjuster had been floating around and getting pounded into the head.
There is a thread, (cant find it), that had 2 or 3 valve adjuster thread marks on the inside of the head where the adjuster had been floating around and getting pounded into the head.
I just posted and haven’t had the time to research old posts. Makes sense something got in there. Especially valve keeper. It’ll be a few days but I’ll post the results. I’m a video guy…it’s easier:Thanks for the input.
JRay, yeah buddy! Your valve keepers and everything still in place? The PO must have over reved mine and lost the keepers. The cam lobe drove the valve spring cap down through the bottom of the valley. Took out a 2 X 2 inch piece of the bottom. A shop patched it with devcon and a piece of 20 thou aluminum.. Didn't hold for me and I replaced the whole matched assy.
Well shit @thuban. Now you gots me thinking another scenario. I was having issues with my carbs. They wouldn’t come back down to idle. Stay reved pretty high until I dropped down in gear and slowly let clutch out. I don’t have a tach installed. Maybe during this fiasco, I lost a keeper? Sounds like a pretty safe bet.
I'm betting you had a tappet nut wasn't tight, the tappet backed out, went over the top of the cam then wedged under it. They "usually just" break the oil fence behind the cam, guess you are the lucky one.....
WOW! None of it sounds good. But if it's just that little piece, have it aluminum welded back in place. The "valleys" as I call them, are not load bearing.
There will probably be some cracking but not a problem to weld.
I don't think this would have anything to do with carburation.
There will probably be some cracking but not a problem to weld.
I don't think this would have anything to do with carburation.
That’s the story I heard! Yeah the tappet nut loosening up and coming off is a very likely suspect!
Sorry.
